Serena Williams will play in the Emilia-Romagna Open next week following her early exit in Rome, Patrick Mouratoglou has confirmed.

The legendary American was beaten 7-6 (8-6) 7-5 by Nadia Podoroska in the 1,000th match of her incredible career at the Internazionali BNL d'Italia on Wednesday.

Williams, who was given a bye into the second round at Foro Italico, was playing her first match since losing to Naomi Osaka in the semi-finals of the Australia Open three months ago.

With the French Open getting under way on May 30, Williams has taken a wildcard to get more time on clay under her belt in Parma.

Mouratoglou, the former world number one's coach, tweeted: "Change of plans: Serena hasn't been competing for a while, and we want to get as many matches under our belt as possible before Roland-Garros - so we're adding the Emilia-Romagna Open to our schedule.

"We'll be back in action next week."

Williams will head to Paris for the second major of the year in her latest attempt at matching Margaret Court's record tally of 24 grand slam singles titles.

Simona Halep suffered a worrying leg injury just over two weeks out from the French Open at the Internazionali BNL d'Italia, where Serena Williams and Naomi Osaka crashed out.

Halep, the 2018 French Open champion, had dominated the first set against Angelique Kerber, winning 6-1, but came off the court with an apparent calf problem with the scores level at 3-3 in the second.

She received treatment but an emotional Halep was forced to withdraw from the clash, the defending champion handing victory to Kerber.

The Romanian was then helped from the grandstand court, leaving the area with strapping on her leg and a heavy limp, raising doubts about her ability to compete at Roland Garros, where she would likely be one of the favourites.

Earlier Williams made her first appearance on the tour since February, losing the 1,000th match of her glittering career to Nadia Podoroska, who reached the semi-finals in Paris last year.

Podoroska prevailed 7-6 (8-6) 7-5, with 23-time grand slam champion Williams not too downhearted by a defeat to an accomplished clay-court player.

"It's tough to have a first match on clay. It was definitely kind of good to go the distance and to try to be out there, but clearly I can do legions better," Williams said. 

"She has a good game, for sure, obviously. She's very consistent. Overall, it was good for me to play such a clay-court player on clay today, but it's a little frustrating. But it's all right. It is what it is.

"I have been training for months, but it feels definitely different on clay to make that last adjustment. Just filling out the game, finding the rhythm. Even sliding and confidence with that, with movement. That's always like a little struggle in the first two matches, and then I'm raring to go."

Osaka has yet to find her footing on clay and the reigning Australian Open champion came up short in the second round as she suffered a surprise loss to Jessica Pegula.

Pegula said after her 7-6 (7-2) 6-2 win: "I know she doesn't love clay, so I just tried to be the clay court player out there today, and it worked just good enough."

World number one Ashleigh Barty had no such difficulties in her 6-4 6-1 over Yaroslava Shvedova, but fourth seed Sofia Kenin was a shock loser to Barbora Krejcikova.

Petra Kvitova was beaten in three sets by Vera Zvonareva but Madrid champion Aryna Sabalenka, last year's French Open champion Iga Swiatek, Elina Svitolina, Karolina Pliskova and Garbine Muguruza all progressed while teenager Coco Gauff knocked out 17th seed Maria Sakkari.

Serena Williams made an unsuccessful return to the WTA Tour as she joined Naomi Osaka in crashing out of the Internazionali BNL d'Italia in the second round on Wednesday.

Williams was playing the 1,000th match of her glittering career against Nadia Podoroska, her first since losing in the Australian Open semi-finals to Osaka in February.

The American has experienced significant success in Rome, winning the title four times, but was always likely to be tested by a player who reached the French Open semi-finals last year.

And that proved the case as she slumped to a 7-6 (8-6) 7-5 defeat despite threatening a second set fightback.

Having won the first set on a tie-break, Podoroska continued to dominate the longer exchanges and went 5-2 up in the second.

From there, Williams won 12 straight points to level matters at 5-5, but Podoroska then claimed a nervy service hold to force the 23-time grand slam champion to serve to stay in the match.

She never came close to doing so as Williams was broken to love, a miscued forehand long giving Podoroska one of the biggest wins of her career.

Earlier in the day, Osaka was defeated in straight sets by Jessica Pegula.

Osaka has made no secret of her discomfort on clay, having never gone beyond the third round at Roland Garros.

All of her 10 WTA singles titles have come on the hard court and she was undone on the red dirt once more as Pegula prevailed 7-6 (7-2) 6-2.

Serena Williams showed there would be no letting up in her relentless pursuit of tennis history as she hit the practice courts with one of the biggest names on the men's tour.

A semi-final defeat to Naomi Osaka at the Australian Open was the latest blow for Williams in her attempt to match Margaret Court's record of 24 grand slam titles.

Stuck on 23 since winning at Melbourne Park in 2017, Williams has gone repeatedly close in the subsequent years without getting her hands on a major trophy.

She took to the courts with Bulgarian ace Grigor Dimitrov, a beaten quarter-finalist in Australia and former world number three, as part of her continuing bid to keep improving and stay focused on those title goals.

Dimitrov could not resist boasting about the prowess of the player he was hitting with, posting a video of their session and writing on Instagram: "My practice partner is better than yours."

He added a goat emoji, signalling his belief that Williams is the greatest of all time.

Williams gestured a fond goodbye to the Australian Open crowds after her loss to Osaka, and became tearful in an after-match news conference when asked if it was a final farewell.

"I don't know. If I ever say farewell, I wouldn't tell anyone," said the 39-year-old.

Her next appearance on tour is expected to be at the Miami Open, starting on March 23, a tournament which has confirmed Williams, Osaka, Bianca Andreescu and Simona Halep among its field.

There was a little sibling envy from Venus Williams on Sunday when she questioned where Serena and Dimitrov were rallying.

"Omg are you guys hitting now? Where is my invite??" Venus wrote.

The next grand slam on the calendar is the French Open, beginning on May 23, while Serena may see Wimbledon, beginning on June 28, as providing her best chance of another slam.

She has won seven times at the All England Club, two behind the record held by Martina Navratilova.

It remains to be seen whether Serena Williams returns to contest the Australian Open in 2022 but amid long-term doubts, Naomi Osaka said "I want her to play forever".

Williams' long-standing bid to equal Margaret Court's record of 24 grand slam titles was put on hold by three-time major champion Osaka, who overpowered the American superstar 6-3 6-4 in the blockbuster Australian Open semi-final.

Not since claiming the 2017 Australian Open trophy has Williams celebrated a slam crown, and the 39-year-old is not getting any younger as she faded into the Melbourne shadows on Thursday.

Williams broke down in tears and cut short her news conference post-match, having been involved in an emotional moment on Rod Laver Arena, where the seven-time Australian Open champion held her hand on her chest and waved to the crowd.

Asked what it means to face Williams as the clock ticks on a legendary career, Osaka – who topped the veteran in the 2018 US Open final – told reporters: "It definitely means a lot.

"Every time I play her, I feel like it's something I'll definitely remember a lot.

"I don't know, it's kind of sad when you say it like that because for me, I want her to play forever. That's the little kid in me."

Japanese star and third seed Osaka will now face Jennifer Brady in Saturday's final as she eyes her second Australian Open crown.

Osaka has gone on to win the title each time after advancing past the round of 16 at a slam – 2018 US Open, 2019 Australian Open and 2020 US Open, while she is in the midst of a 20-match winning streak.

Asked what makes her so hard to beat in finals, Osaka added: "For me, I have this mentality that people don't remember the runners-up. You might, but the winner's name is the one that's engraved.

"I think I fight the hardest in the finals. I think that's where you sort of set yourself apart. It's the other person who won as many matches as you did. It's something that I think, it's like the biggest fight."

Serena Williams refused to confirm whether she made her last Australian Open appearance after breaking down in tears and leaving her news conference following a semi-final defeat to Naomi Osaka.

Bidding to equal Margaret Court's record of 24 grand slam titles – having last won a major in 2017 – Williams was overpowered 6-3 6-4 by third seed Osaka in Melbourne on Thursday.

It was Williams' first semi-final defeat at the Australian Open following eight consecutive victories in the final four of the year's opening slam.

The 39-year-old American star cut an emotional figure afterwards on Rod Laver Arena, where she held her hand on her chest and waved to the crowd after fans were allowed to attend following a five-day coronavirus shutdown.

Asked about the moment, seven-time Australian Open champion Williams told reporters: "The Aussie crowd is so amazing, so it was nice to see."

When pressed if it was a Melbourne farewell, Williams replied: "I don't know. If I ever say farewell, I wouldn't tell anyone."

A tearful Williams then suddenly ended her news conference after being asked about the match.

Williams was visibly and vocally frustrated against Osaka after seeing an early 2-0 lead slip.

Osaka reeled off five consecutive games and six of the next seven to close out the set before taking complete control against the former world number one.

Williams finished with 24 unforced errors against the three-time slam champion and 2019 Australian Open winner.

At the start of her post-match duties, Williams said: "I wouldn't say I was nervous. The difference today was errors. I made so many errors today.

"Honestly, it was opportunities where I could have won. I could have been up five-love. I just made so many errors."

"I felt like I was hitting well," Williams added. "I was hitting well this whole tournament. Even the first couple games I played well. Even then I had so many opportunities.

"I don't know. Just made too many mistakes there, easy mistakes. Not like I was on the run or anything, they were just easy, easy mistakes."

Serena Williams' quest for a record-equalling 24th grand slam title has been delayed again after being overpowered 6-3 6-4 by third seed Naomi Osaka in the Australian Open semi-finals.

Stuck on 23 slam championships since reigning supreme at Melbourne Park in 2017, Williams was hoping to move within a step of matching Margaret Court's record.

But the 39-year-old former world number one was taken down by three-time major champion Osaka in a blockbuster battle of the big hitters on Thursday.

Japanese star Osaka will now face either Jennifer Brady or Karolina Muchova in Saturday's final as she eyes her second Australian Open crown.

Osaka – the youngest player remaining in the draw – initially struggled under the beaming Melbourne sun as fans returned to Rod Laver Arena following a five-day state-wide lockdown after a coronavirus outbreak.

She was in all sorts, struggling on serve and tallying five unforced errors through two forgettable games as Williams raced out to a 2-0 lead.

Osaka – boasting a 3-0 record in grand slam semis – faced a 30-40 deficit and potential 0-3 hole before digging deep to hold for the first time.

It proved to be a turning point for Osaka, who went on a roll by reeling off five successive games and six of the next seven to take complete control.

The tables turned on Williams, who saw her unforced-error count balloon out to 16 while only hitting four winners in the opening set.

Williams – the oldest woman to reach the semis in Melbourne in the Open Era – carried a flawless Australian Open semi-final record into the contest, having won all eight of her previous final-four showdowns.

But Williams cut a frustrated figure at the start of the second set as she yelled at herself "make a shot" amid her demise – Osaka breaking in the first game before consolidating.

However Osaka, who has gone on to win the title each time after advancing past the round of 16 at a slam – 2018 US Open, 2019 Australian Open and 2020 US Open, lost her way when serving at 4-3 as three double faults saw her broken by Williams.

Williams, beaten by Osaka in an infamous US Open final three years ago, regifted the compliment the very next game, Osaka hitting three stunning winners to break to love before sealing her place in the women's decider.

Data slam: Osaka stays hot
She has now won 20 consecutive matches since losing while on Fed Cup duty for Japan last February. A 21st successive victory would yield a fourth slam triumph.

WINNERS/UNFORCED ERRORS
Williams – 12/24
Osaka – 20/21

ACES/DOUBLE FAULTS
Williams – 3/1
Osaka – 6/8

BREAK POINTS WON
Williams – 2/7
Osaka – 4/4

Jennifer Brady believes a two-week hard quarantine upon arriving in Australia helped her make a run to the semi-finals at Melbourne Park.

As one of the 72 Australian Open entrants that had potentially been exposed to COVID-19 on chartered flights to Melbourne, Brady was forced to stay in a hotel room for a fortnight ahead of the first grand slam of the year.

However, the 25-year-old booked her place in the final four on Wednesday by coming from behind to defeat Jessica Pegula 4-6 6-2 6-1 in an hour and 40 minutes on Rod Laver Arena.

While some players voiced their displeasure with the conditions they were faced with in self-isolation, Brady felt the period served her well.

"I was pretty much going non-stop since June of last year. I was playing World TeamTennis, then played tournaments in the US, then went over to Europe and was training in Europe till December," said Brady.

"I didn't have any weeks off. Mentally I was feeling a little bit fried, to be honest. I think I used that two weeks to kind of reset mentally and also physically, just give myself, my mind, my body a little bit of a rest.

"I would say I didn't really have high expectations on myself to do well. I came out of the quarantine, and then we were lucky enough to have a separate tournament for us who were in the hard lockdown. I was lucky to get a couple matches in there before starting here in the Australian Open."

The 22nd seed will take on Karolina Muchova in the last four, the Czech having stunned world number one Ash Barty earlier in the day. In the other half of the draw, Serena Williams will take on Naomi Osaka.

Brady hopes to get an opportunity to challenge herself against 39-year-old veteran Williams, who is chasing a record-equalling 24th major singles title.

"I think just being in the same draw as Serena is obviously... when she retires, if she retires, it's going to be something I'll be extremely grateful for. I hope I get to play her before she retires," said Brady.

"Yeah, I think she's the G.O.A.T. She's the greatest of all time and definitely will be the greatest of all time."

Brady made her first grand slam semi-final appearance at last year's US Open, when Williams and Osaka were also in the final four.

She suffered a three-set loss to Osaka on that occasion, but she is pleased to be performing on a par with the Japanese and Williams.

"I think it says a lot. They're obviously great, great tennis players, champions of the sport. To be categorised in the same group as them, I'll take that as an honour," said Brady.

"I think it's a huge achievement for me to make the semi-finals here. I look to make the finals, so we'll see."

Only Muchova stands between Brady and a first major final and fans will be able to attend after lockdown was lifted in Victoria, with a crowd of 7,477 – approximately 50 per cent capacity – allowed for each session.

Brady said of her next opponent: "She's crafty. She looks to move forward, has an all-court game. She's really athletic.

"I hope it will be a good, competitive match. Yeah, I'm looking forward to it."

Serena Williams admitted it felt like stepping back in time as her movement and power came together to overwhelm Simona Halep at the Australian Open.

It had been just over 18 months since Halep destroyed Williams in the Wimbledon final, and with the American great approaching her 40th birthday, prospects of a 24th grand slam title have appeared to fade.

Into the conversation on Tuesday strolled a revitalised Williams, a woman who has been proving a point and defying expectation for coming up to a quarter of a century.

Williams is simply not having it that her days as a winner might be over, which is why she and coach Patrick Mouratoglou are always seeking marginal gains.

Dogged by an Achilles injury since the US Open last September, Williams feels over that, and a 6-3 6-3 quarter-final win over Halep attested to that being the case.

More than that, though, Williams noticed the years fall away as she dashed around the court, thumping groundstrokes with abundant power and often plenty of precision.

Speaking of the movement returning, Williams said: "It was something that Patrick and I did discuss. I just wasn't able to incorporate it as much as I would have liked to.

"But once I was able to get on the court, I was able to incorporate it as much as I could. Movement has always been one of my strengths, and so it's actually more natural for me to move than for me not. So it was just kind of, like, 'Oh, that's how I used to move', so it's pretty good.

"I'm happy that I'm doing that again and that I put it back into my game. I think I was more focused on other things and not focused on something that is actually a strength of mine, has always been a strength of mine, and I had to refocus on that."

She faces Naomi Osaka next for a place in the final. It reads like a match-up of an all-time great against a player who could over time join her in that pantheon.

Osaka is pursuing a fourth grand slam title, while Williams wants the 24th as much as she craved the first, given it would move her alongside Margaret Court at the top of the all-time list.

The veteran American's most recent slam title came while pregnant in Australia four years ago, with Williams dealt four final defeats since, including a notable one to Osaka at the 2018 US Open.

If Osaka was watching Williams on Tuesday, as she surely was, the Japanese player could have only been impressed.

When asked about how she was matching and often out-matching Halep even in the longest rallies, Williams paused to consider when she was last able to boss such exchanges.

"It's definitely been a minute. It's been a long minute," she said with a smile. "I think 19... 1926, the summer of 1926 I think was the last time I felt that.

"But I'm good at rallying and I have to embrace the things I'm good at. I'm good at playing power, I'm good at hitting a hundred balls.

"That's one thing that's unique about me that I just need to kind of accept and embrace and just be good at both."

Williams and Osaka may have a crowd on Thursday for the semi-final, or they may not. Melbourne remains in lockdown but spectators could be back on Rod Laver Arena for the clash of two of the sport's biggest personalities.

Addressing that prospect, Williams indicated she would have mixed emotions.

"I love having the people there, obviously. But at the same time, it's kind of nice to not have, like ... more pressure when there is people in the stands," Williams said.

"So I think either way it's really a win-win situation. That's kind of how I look at it."

Fast-footed on the court, quick to sidestep off it, Williams is convinced she can push Osaka hard, perhaps heartened by a narrow win when they met in an exhibition match in Adelaide last month.

"I've got to keep going. Obviously I have an incredible opponent to play, so it would be nice to hopefully keep raising the level of my game. I'm going to have to," Williams said.

Halep said Williams "was stronger in the important moments", and she too noticed her opponent showing something near vintage form.

"Yeah, she's moving better and she hits strong," Halep added. "I feel like she's in a good shape now. She has a really good game. Always did..."

Serena Williams is in the Australian Open semi-finals for the first time since she last won a grand slam title, beating Simona Halep to set up a mouthwatering clash with Naomi Osaka.

The American great gained revenge for her Wimbledon final defeat to the Romanian two seasons ago as she conjured a 6-3 6-3 win on Rod Laver Arena.

Halep dropped just four games in that stunning grass-court success in 2019, the third of four grand slam finals that Williams has lost since landing her 23rd major in Australia four years ago.

The 24th title has remained frustratingly elusive, with Williams one away from matching Margaret Court's record haul, but perhaps this is the week where that changes.

She must get past Osaka, her heir apparent as the figurehead for the women's game, but Williams showed her prowess in this match, devastatingly proving a point.

Her power won out, with 24 winners to just nine from Halep, although the 33 unforced errors from Williams showed there is room for improvement in precision.

The tone was set from the first point, Williams with a brilliant forehand service return winner on the forehand side on her way to an immediate break of serve.

Halep forced her way level but Williams raised the tempo in the sixth game and a deep forehand into the Romanian's backhand corner secured a 4-2 advantage.

Williams served out the set to love at the first opportunity but then dipped early in the second set, Halep pinching a break when the American volleyed waywardly at the net.

What proved a consistent theme was Halep's struggle to hit through her opponent, and the two-time grand slam winner could not capitalise on a 3-1 lead in that second set, dropping five successive games as the 39-year-old Williams began to turn on some vintage form.

Dismissive of the often weak Halep serve, Williams swept through to the clash with Osaka.

"I definitely think this was the best match I've played this tournament for sure," Williams said. "I had to, going up against the number two in the world. I knew I had to do better and that's what I did, so I'm excited."

Looking forward to facing Osaka, Williams said in her on-court interview: "She's such a strong player on the court and such an inspirational person off the court, which I think is really cool. I've been watching her and I'm sure she's been watching me."

Former world number one Naomi Osaka is unfazed about her record at grand slams as she eyes consistency after reaching the Australian Open semi-finals.

Osaka will face either 23-time slam champion Serena Williams or Simona Halep in the semis following Tuesday's emphatic 6-2 6-2 win over Hsieh Su-wei in Melbourne.

Three-time major winner Osaka has gone on to win the title each time she has reached the quarter-finals of a slam – beating Hsieh en route to her 2019 Australian Open triumph.

Asked about the record, Osaka told reporters: "I don't really care about the stat. Just because I've only been to four quarter-finals.

"It feels something like 20. That would be cool. But four, it's not really doing too much for me.

"I would be more impressed if I didn't lose in finals. If it says 10-0 in finals. But the fact is if I don't reach the finals, I lose in the fourth round or the third round.

"For me, I'm happy to be more consistent. I think I'm being more consistent since New York, so that's the ultimate goal for me."

Osaka – in the midst of a 19-match winning streak – overpowered veteran Hsieh on Rod Laver Arena, where the Japanese star hit 24 winners and just 14 unforced errors, while she lost just two of her 25 first-service points.

It does not get any easier for Osaka, with record-chasing Williams or two-time slam champion Halep standing in the way of a trip to Saturday's decider at Melbourne Park.

"I played both of them before I think multiple times," Osaka – confident after saving two match points against Garbine Muguruza in the last 16 – said.

"Halep, I don't really like playing her. She's someone that's really tough, someone that gets the ball back every time. For me it's definitely a mental and physical battle.

"Of course, the same goes for Serena. She's Serena, someone that I feel really intimidated when I see her on the other side of the court."

Serena Williams is moving better than she has in years, according to her coach Patrick Mouratoglou.

Williams, 39, has looked in good form at the Australian Open as she eyes a record-equalling 24th grand slam singles title.

The American has dropped just one set on her way to the quarter-finals, in which she faces Simona Halep on Tuesday.

Mouratoglou said Williams' movement was the best it has been in several years.

"First of all, it's something that we have put the emphasis on because in tennis that's probably one of the most important things. If you are late on the ball, you can't do what you want to do. Sometimes you don't even touch the ball," he told a news conference on Monday.

"It's a sport where you have to be able to move fast from side to side and long enough. It's something that probably in the last two, three years, this had consequences for Serena.

"Even more, when you're not in a good day, you need a plan B. To be able to have a plan B, you have to be able to move well. If you can't move well, there is no plan B. The only plan is attack.

"I think it cost her a few important matches. So we have decided to find a way to bring back the footwork that she used to have in the past. I feel like she's done a great job. She's moving much better."

Williams last won a major title in Melbourne in 2017, losing four grand slam finals since then.

With all eyes on her as she aims to equal Margaret Court's record of 24 grand slam singles titles, Mouratoglou insisted that mark was not an obsession for Williams.

"Does she need that validation? I don't think she needs that validation.  But, I mean, clearly she came back to tennis to win some other grand slams, so that's for sure the goal," he said.

"Now, she's not as obsessed with the 24 than most of the people in the tennis world, but definitely she wants to win grand slams. That's the only reason why she came back to tennis."

Simona Halep set up a quarter-final duel with Serena Williams after showing admirable character to battle back from a set down to beat Iga Swiatek 3-6 6-1 6-4 and seal her 100th grand slam match win.

Halep and Swiatek put on a thrilling show in the night session on Sunday, as the Romanian two-time grand slam champion demonstrated her fighting spirit to come from a set down and reach the last eight.

Swiatek took charge in the first set after saving the first two break points of the contest, eventually putting herself in a commanding position as she won the 10 of the final 11 points of the set, but Halep remained focused as her 19-year-old opponent began to wobble in the second.

Halep then snuffed out any threat of a turnaround by breaking back straight after losing on her own service in the decider and she went on to set up a meeting with Williams, who had overpowered Aryna Sabalenka earlier in the day.

Naomi Osaka also advanced, though she was by no means comfortable, while Hsieh Su-wei beat Marketa Vondrousova in straight sets.

HALEP'S REVENGE

Halep's clash with Swiatek was their first since the French Open last October, when Swiatek ran out a 6-1 6-2 winner and went on to claim her maiden major title.

Revenge was on the cards at Melbourne Park and Halep got the job done impressively, showing her mettle to return from a set down.

"Well, I thought before the match that I have to be a little bit more aggressive than Paris. In Paris I have been very far back, and my ball didn't go through the court," the second seed said. "So, I thought that it's a better chance to go and hit.

"The pressure came from the way I played the last match against her. I just expected a better game from myself, which I did, and I'm really happy about that."

Halep accepts facing Williams will be an entirely different challenge, but she remains confident despite lauding the American a "legend" in her on-court interview.

"Of course it's different, she's the only one with 23 grand slams, so you cannot compare Serena with all of us, because we do not have so many grand slams," Halep added.

"But when I step on the court, it's just another opponent, and always I'm focused on myself more than I focus on who I play. We played so many times. I know what to expect. I will just try to do my game, and I will be confident."

WILLIAMS ON COURSE

All eyes are on Williams yet again, as she hopes to equal Margaret Court's record of 24 grand slam titles – and on the evidence of her latest win, she will take some stopping as she won 6-4 2-6 6-4.

Williams revealed she had to cope with a little off-court stress this week with her clothing line, and Sabalenka certainly kept the pressure up as the 22-year-old took the second set.

But Williams responded well to the seventh seed, who became the first player to take a set off the former world number one. Williams said she remained confident despite that setback.

"Like I said on the court, I just felt like even games that I lost, I was so close to winning. Not all games, but probably most of those games," she said. "I just needed to play better on the big points.  I knew that I could. I still hadn't reached my peak. I was like, 'Okay, Serena, you got this, just keep going.'"

OSAKA RELEASES HER ANGER

Osaka was in a real spot of bother against Garbine Muguruza, but saved two match points.

The 2019 champion Osaka steadied herself and felt more composed after a brief show of frustration, as she struck the ground with her racquet.

Ultimately, she emerged a 4-6 6-4 7-5 victor, and Osaka felt letting frustration get the better of her for a moment helped her cause.

"On the first match point, I was just thinking that I didn't hit a decent serve that entire game, so I should really focus on my serve," he said. "I feel like my serve stats were pretty good that set, so I was just telling myself to do better.

"Then on the second point, when the rally started, I just told myself not to push [the ball] but also don't do something crazy and make a really bad unforced error. I felt the entire match I was overthinking. There was a moment when I got angry and hit my racquet on the ground. I feel like I released a lot of the thoughts that I had. It just made me go more into instinct-based tennis."

She will face Hsieh next, the world number 71 having beaten Vondrousova – ranked 51 places higher – 6-4 6-2.

Serena Williams calmed injured fears after coming through a thrilling back-and-forth against Arnya Sabalenka to reach the quarter-finals of the Australian Open.

Williams, who is pursuing a record-equalling 24th career grand slam and her first major victory in four years, prevailed 6-4 2-6 6-4 after more than two hours on court against seventh seed Sabalenka.

Her struggles during the second set appeared partly attributable to a fall but Williams recovered her poise and the 39-year-old does not expect any ill-effects in a last-eight showdown against either Simona Halep or Iga Swiatek.

"I don't think so. It didn't hurt at all. I didn't roll my ankle, so that was good," she told reporters.

"Yeah, I think it was just dramatic, me being dramatic.

"My first thought was, 'Not another ankle sprain in Australia'. But I knew immediately that it wasn't.

"Then I was more embarrassed than anything. I was like, 'Oh, my goodness'."

Williams moved well throughout the contest, assuaging any lingering concerns over Achilles problems that have dogged her of late - even manging to rally when Sabalenka reeled off three consecutive games from 1-4 down in the decider.

"I've worked really hard on my movement. Yeah, I like retrieving balls. I mean, obviously I like to be on the offense, but I can play defence really well, as well.

"I do get a lot of balls back when I need to. I didn't think about my Achilles. It's so good to not think about it. Oh, my goodness. It's been a problem actually since 2018.

"I just never want that problem again. It feels really good to just play and to run, to not feel that. It's a great relief."

Arguably Williams' greatest inconvenience around the match was not a physical one, after she had to participate in a Saturday conference call to avert an "emergency" at her clothing business.

"Tennis is a lot less stressful. I don't have to manage a team. I do manage a team actually, but it's different," she chuckled. "Even though I am the CEO of my tennis team, it's definitely different.

"I think a part of me loves being on the court because it's free-flowing. It's not like I have to kind of just manage and make sure everyone is able to perform.

"I have a second career and it's fun. One of our main players, our employees, had an emergency. You got to step it up when you got to step it up.

"I was smart about that. I scheduled a call directly after my practice. I was like, 'Okay, I can do it early and still have the rest of the day to relax'.

"And it was during [Williams' daughter] Olympia's nap, so it was perfect."

Serena Williams moved a step closer to a record-equalling 24th grand slam title after outlasting Aryna Sabalenka in an absorbing battle to reach the Australian Open quarter-finals.

Williams – in pursuit of Margaret Court's record slam haul of 24 – has not tasted major success since winning the Australian Open in 2017.

But former world number one Williams and her bid to match Court remains on track following Sunday's thrilling 6-4 2-6 6-4 victory over seventh seed Sabalenka after more than two hours.

No fans were allowed to attend Melbourne Park amid a coronavirus lockdown in Victoria, but there was still plenty of noise inside Rod Laver Arena in a battle between two big hitters.

Williams, who reached 90 Australian Open wins in 101 appearances in Melbourne last time out – she has played and won more matches than any other woman in the tournament's history, prevailed in a tense opening set.

After fending off a break point in the seventh game, Williams – moving extremely well against the 22-year-old – was gifted a second break-point chance of her own three games later and she pounced as Sabalenka fired a forehand into the net.

The seven-time Australian Open champion hit 12 winners and just nine unforced errors in a fast and ferocious first set.

Williams owned a career 53-8 record in last-16 matches at grand slams heading into the contest – last falling at this stage when she pulled out ahead of her French Open showdown with Maria Sharapova in 2018, while her last match loss at this stage came in Melbourne in 2014.

But Sabalenka was unperturbed, the Belarusian – eyeing her maiden slam quarter-final – an unstoppable force against a helpless Williams in the second set, breaking in the first, third and fifth game.

Williams, who only made 36 per cent of her first serves, was moved around the court as she dropped a set for the first time at this year's Australian Open.

Having cut a frustrated figure in the second set, Williams emerged with renewed figure in the decider – the 39-year-old claiming the decisive break of serve in the fourth game for a 3-1 lead before digging deep to consolidate.

Sabalenka reeled off three consecutive games to put the match back on serve, but she was unable to maintain her charge against Williams, who closed out the match on her opponents' serve.

Data Slam: Serena steps up on serve
Not much went right for Williams on serve in a lopsided second set. But when it mattered most, the 12th seed stepped up by serving at 71 per cent in the third – winning 17 of 22 first-serve points against Sabalenka.

WINNERS/UNFORCED ERRORS
Williams – 30/26
Sabalenka – 24/36

ACES/DOUBLE FAULTS
Williams – 9/8
Sabalenka – 4/4

BREAK POINTS WON
Williams – 4/9
Sabalenka – 4/11