Paula Badosa underlined her credentials as an Australian Open contender by capturing the Sydney Classic title on Saturday.

The Spaniard beat French Open champion Barbora Krejcikova 6-3 4-6 7-6 (7-4) to claim the trophy in a battle of two of the breakout stars on the WTA Tour.

Krejcikova was considered a doubles specialist until last season, when she soared from 65th to fifth place in the world rankings, on the back of Roland Garros glory and runs at both Wimbledon and the US Open.

New York-born Badosa also shot up the rankings in 2021, surging from 69th to number eight by the year's end after winning titles in Belgrade and Indian Wells.

Her performance in winning the latter, a prestigious WTA 1000 event, pointed to Badosa being a likely challenger for hardcourt success in Australia.

She beat Krejcikova during that Californian tournament and repeated the feat in Sydney, the hard-hitting Spaniard maintaining a 100 per cent winning record in WTA finals.

Badosa said: "I feel really bad because I'm playing against a friend and playing a match like today where I think we both went to the limit and losing, it is never easy.

"But I want to congratulate you for everything. We both broke into the top 100 a few years ago, and now we're playing big finals.

"For me, it's an honour to see you grow, you're an amazing player and a grand slam champion."

Badosa begins her Australian Open mission in Melbourne against a home player in Ajla Tomljanovic next week, while Krejcikova has a first-round clash with German Andrea Petkovic.

Chris Evert has been diagnosed with ovarian cancer and has begun chemotherapy, the American tennis great announced.

The 67-year-old Evert, whose on-court battles with Martina Navratilova in the 1970s and 1980s provided one of the greatest tennis rivalries, won 18 grand slam singles titles in a much-lauded career.

Evert told ESPN, for whom she has worked as a match analyst, that she underwent the first of six rounds of chemotherapy this week.

It means Evert has not travelled to Melbourne to work at the Australian Open, which begins on Monday. She said she would be providing analysis from home during the tournament.

The cancer was discovered after a preventive hysterectomy and Evert said it was found at an early stage.

In a message posted on Twitter, she said: "I wanted to share my stage 1 ovarian cancer diagnosis and the story behind it as a way to help others. I feel very lucky that they caught it early and expect positive results from my chemo plan."

Speaking to ESPN, she added: "I've lived a very charmed life. Now I have some challenges ahead of me. But, I have comfort in knowing the chemotherapy is to ensure that cancer does not come back.

"As someone who has always had control over my life, I have no idea how I'll respond to chemotherapy. I have to give in to something higher."

Evert's sister Jeanne died from ovarian cancer in February 2020.

"When I go into chemo, she is my inspiration," Evert added. "I'll be thinking of her. And she'll get me through it."

Messages of support poured in for Evert, with Navratilova writing: "We are all with you and behind you Chrissie, you are a true champion and I have no doubt you will conquer this nasty opponent with nary a sweat!"

Billie Jean King, a fellow American tennis legend, said she and her partner Ilana Kloss would have Evert "in our thoughts and prayers".

"Sending you so much love and healing thoughts, @ChrissieEvert ... and we wish you strength as you face this battle. You are one of a kind, and there are so many who love you," King said.

Among current WTA Tour stars, there were Twitter messages of support from the likes of Victoria Azarenka, Garbine Muguruza, Madison Keys, Paula Badosa and Ons Jabeur.

Tracy Austin, a fellow player-turned-analyst, told Evert: "You are one of the strongest people I know. There are so many of us that will be with you every step of the way."

Daria Kasatkina reached her second semi-final in as many weeks with a straight-sets victory over Garbine Muguruza at the Sydney Tennis Classic on Wednesday.

The world number 26, who was defeated by Amanda Anisimova in the Melbourne Summer Set 2 semi-finals last week, beat second seed Muguruza 6-4 6-4.

Kasatkina held throughout the opening set, landing 67 per cent of her first serves, and saw the job through in the second despite a couple of early breaks for Muguruza.

It is the Russian's first win over a top-five opponent since beating Caroline Wozniacki at the 2018 French Open.

She will now face fifth seed Paula Badosa, who saw off Olympic gold medallist Belinda Bencic 7-6 (8-6) 3-6 6-3 in an entertaining match lasting two hours and 35 minutes.

The other semi-final in Sydney will be contested between Anett Kontaveit and Barbora Krejcikova, who advanced past Ons Jabeur and Caroline Garcia respectively.

Krejcikova proved far too strong for Garcia, prevailing 6-0 6-2 in 70 minutes, while Kontaveit was in action for just 43 minutes before being handed a walkover win in her match.

Jabeur had targeted "payback" against Kontaveit after her quarter-final opponent pipped her to the final WTA Finals spot in November, but injury cost her the chance to do so.

Having lost the first set 6-4, Jabeur – who eliminated Petra Kvitova in the previous round – felt unable to continue due to a lower back injury.

At the Adelaide International 2, three of the five Americans in action made it through to the semi-finals.

Alison Riske's clash with compatriot Madison Brengle ended early due to the latter retiring with the first set level at 3-3. Tamara Zidansek awaits Riske after beating Lauren Davis 7-6 (7-4) 7-6 (9-7).

Coco Gauff and Madison Keys will meet in the other semi-final, meanwhile, following victories over Ana Konjuh and Ludmilla Samsonova in two and three sets respectively.

Novak Djokovic has been drawn against Miomir Kecmanovic in the opening round of the Australian Open as the defending champion awaits to hear if he can stay in the country.

World number one Djokovic was last week given a medical exemption to enter Australia, despite not being vaccinated, only for border officials to block it upon his arrival.

The 20-time grand slam winner was detained for four days while waiting to appeal the case on Monday, which went in his favour at Melbourne Circuit Court.

Djokovic has since started training ahead of the Australian Open, which begins next Monday, though immigration minister Alex Hawke may yet cancel his visa for a second time. 

A decision on whether Djokovic can compete in the first grand slam of the year, which he has won a record nine times, could be made on Thursday.

Should he be given the all clear to take part, Djokovic will face compatriot Kecmanovic in the first round at Melbourne Park.

Thursday's draw, which was delayed by one hour and 15 minutes for unspecified reasons, also saw fellow 20-time grand slam winner Rafael Nadal paired with Marcos Giron.

Nadal is in the same half of the draw as Djokovic, meaning the pair could meet in the semi-finals, while third seed Alexander Zverev is also in the top half.

Second seed and 2021 finalist Daniil Medvedev is in the bottom half along with Stefanos Tsitsipas and will take on Henri Laaksonen first up.

In the women's draw, Australia's world number one Ash Barty will begin her quest for glory on home soil against a qualifier.

The top seed is on a collision course with defending champion Naomi Osaka, who goes face-to-face with Camila Osorio in round one on her return from a four-month break.

Reigning US Open winner Emma Raducanu is up against Sloane Stephens, who won the New York major in 2017, while Storm Sanders awaits second seed Aryna Sabalenka.

Ons Jabeur eliminated Petra Kvitova from the Sydney Tennis Classic and immediately set her sights on "payback" against next opponent Anett Kontaveit.

World number 10 Jabeur had lost her previous four meetings with Kvitova, but she emerged victorious on Wednesday with a 6-4 6-4 win to reach the quarter-finals.

Jabeur recovered from 3-1 down in both sets at Ken Rosewall Arena and converted half of her six break points on her way to setting up a meeting with Kontaveit.

The two will resume their friendly rivalry after Kontaveit overcame Romanian qualifier Elena-Gabriela Ruse 6-3 6-1.

Jabeur lost out to Kontaveit for the last WTA Finals spot in November and is now seeking revenge in the final warm-up event ahead of the Australian Open.

"Anett is a great player. We had our moments last year," Jabeur said. "I told her, 'You're obsessed with me, you always follow me, so stop [smiling]'.

"I know the pressure is on me, not really on her. But maybe I can get some payback for last year."

Garbine Muguruza is also through to the last eight in Sydney thanks to a 6-1 7-6 (7-4) win against Ekaterina Alexandrova.

The two-time major champion will face Daria Kasatkina, who beat Elise Mertens 6-3 6-4, for a place in the semi-finals.

Third seed Barbora Krejcikova survived a brief fightback from Jaqueline Cristian to advance 6-1 7-5, meanwhile, and Paula Badosa beat home hope Ajla Tomljanovic 6-3 6-4.

There was disappointment for in-form Elena Rybakina, who thrashed Emma Raducanu on Tuesday but had to withdraw from her clash with Caroline Garcia with a thigh injury.

At the Adelaide International 2, Coco Gauff prevailed 6-3 5-7 6-3 in her battle of the teenagers showdown with Marta Kostyuk.

Gauff is one of five Americans in the quarter-finals along with Madison Brengle, Alison Riske, Lauren Davis and Madison Keys, who beat Tereza Martincova 6-1 6-3 to advance.

US Open champion Emma Raducanu suffered the heaviest defeat of her professional career at the hands of Elena Rybakina at the Sydney Tennis Classic.

The ninth seed needed just 55 minutes to storm to a 6-0 6-1 victory to set up a meeting with Caroline Garcia in round two.

This was only Raducanu's eighth appearance in a WTA main draw and the 19-year old had not played since November having contracted COVID-19 and then withdrawn from the Melbourne Summer Set last week.

Rybakina lost only 11 points on serve in the match, sending down four aces. Raducanu, by contrast, struggled badly: the Briton gave up six double faults and won just two points behind her second serve.

"My serve is a weapon, so I'm always working on it and trying to find some variety," said Rybakina. "For sure, it's my game to play aggressive and my serve is helping a lot."

Elsewhere in Sydney, Olympic gold medallist Belinda Bencic beat Beatriz Haddad Maia 6-3 6-2 in her first match of the year and will now face France's Oceane Dodin.

Home favourite Ajla Tomljanovic defeated Anna Karolina Schmiedlova in straight sets, while world number 20 Elise Mertens also progressed.

At the Adelaide International 2, Coco Gauff looked in strong form as she dispatched Katerina Siniakova 6-1 6-2, while fellow seed Tamara Zidansek beat Heather Watson in a three-set battle.

There was a shock for top seed Aryna Sabalenka, though, as she fell 5-7 6-1 7-5 to Sweden's Rebecca Peterson, who celebrated her first win over a top-five player, while American Lauren Davis beat seventh seed Jil Teichmann in three sets.

Ninth seed Sorana Cirstea lost in straight sets to Anhelina Kalinina, but eighth seed Liudmila Samsonova beat Mayar Sherif.

Ons Jabeur made an impressive start to 2022 with a routine win over Astra Sharma at the Sydney Tennis Classic.

Last year's Wimbledon quarter-finalist needed less than an hour to win 6-1 6-3 in her first match of the year and set up a meeting with Petra Kvitova, who has won all three of their previous contests.

There was also a strong performance from Daria Kasatkina, who defeated eighth seed Sofia Kenin 6-4 6-0 to progress.

Fourth seed Anett Kontaveit overcame Shuai Zhang 6-3 6-3 while fifth seed Paula Badosa was a straight-sets winner against 2017 French Open champion Jelena Ostapenko.

There was a surprise at the Adelaide International 2 as second seed Elina Svitolina was undone by the brutal serving of Madison Keys.

The American sent down 14 aces and won all but five points on her first serve to triumph 6-2 6-4.

Compatriot Alison Riske also progressed, beating Magda Linette 6-4 6-4, but Shelby Rogers lost to Marta Kostyuk.

Marketa Vondrousova, who had not played since losing in the Kremlin Cup semi-finals to Kontaveit in October, came from a set down to beat Viktorija Golubic.

The fifth seed battled through 5-7 6-4 6-3 in just under two and a half hours and will now face Ana Konjuh in the last 16.

Ash Barty defeated Elena Rybakina in straight sets to claim the Adelaide International title, while Simona Halep clinched silverware in Melbourne.

World number one and heavy favourite Barty prevailed 6-3 6-2 against Rybakina to claim the Adelaide title for a second time in three seasons.

The 25-year-old recovered from 40-15 down in the seventh game and went on to immediately earn the only break of the opening set.

Barty did not look back as she held throughout the second set, meaning she went 35 consecutive games without losing serve to conclude the tournament.

After securing a 14th WTA singles title in a little over an hour, Barty now turns focus to next week's Sydney Tennis Classic ahead of beginning her Australian Open campaign.

"I feel good leading up to an Australian Open like I have every year," Barty, who hit 17 winners to 13 unforced errors, said after seeing off Rybakina. 

"Each and every preparation is unique. We take it for what comes and what it is, move on, try and do the best that we can in every opportunity.

"It has absolutely no effect on the way that I prepare or the way I'm thinking leading forward just because it's a Grand Slam. It doesn't change for us."

Halep, one of Barty's likely rivals for the Australian Open crown, also made a bright start to the year by overcoming Veronika Kudermetova in the Melbourne Summer Set 1 final.

The number two seed, who is aiming to put last year's injury-ravaged and trophyless season behind her, came out on top 6-2 6-3.

She recovered from an early break down in the first set and again in the second to make it 23 career titles, and a first since the 2020 Italian Open.

It could easily have been a different story, however, as Kudermetova had three break points to move 3-0 ahead in the second set, but the Russian could not take full advantage.

Amanda Anisimova defeated Aliaksandra Sasnovich at the Melbourne Summer Set 2 final to claim the first WTA title of the season, and her second overall.

Belarusian qualifier Sasnovich hit back in style to take the second set 6-1 after losing the opener 7-5, but Anisimova recovered from a break down to edge the deciding set 6-4.

In doing so, Anisimova became the first American to win a title on Australian soil since Sofia Kenin's Australian Open triumph in 2020.

Ash Barty moved a step closer to a second Adelaide International title in three seasons as she crushed defending champion Iga Swiatek's hopes in the semi-finals.

Competing as a stepping stone towards her principal goal of challenging for the Australian Open title later in the month, home favourite Barty sped to a 6-2 6-4 win over the 2020 French Open winner.

She served fewer aces than Swiatek – five to the seven fired down by the 20-year-old Pole – but Barty's powerful forehand proved decisive as she made snappy work of ending the contest.

Barty will face Elena Rybakina in Sunday's final, after the Kazakh beat Japan's Misaki Doi 6-4 6-3. Queenslander Barty beat Dayana Yastremska in the 2020 final.

Having won the French Open and Wimbledon already in her career, Barty will be the favourite at the Australian Open, which begins on January 17 in Melbourne.

The world number one, by seeing off ninth-ranked Swiatek, boosted her win-loss record against top-10 WTA rivals to 8-1 since the beginning of last year.

Barty said, quoted on the WTA website: "It is exciting to be able to play well here in Australia. This is where I want to play my best tennis. I want to give myself an opportunity to play for titles in Australia.

"It's something really exciting to start the year off as an Aussie player in front of our home fans."

Reflecting on a positive performance, Barty, who has also reached the doubles final with Storm Sanders, said: "I felt like on Iga's service games I was able to get into most of them, which is important when you're playing someone who can dominate with that first ball and first strike.

"I felt like I was able to build pressure over time, making her play a lot of balls on her service games, not giving her too many cheapies."

Swiatek is entered into next week's Sydney Classic and learned on Saturday that she faces a testing opener there, having been drawn to face Great Britain's US Open champion Emma Raducanu in a standout first-round match.

At the Melbourne Summer Set 2 tournament, Russian third seed Daria Kasatkina suffered a shock 6-2 6-0 semi-final defeat at the hands of American world number 78 Amanda Anisimova.

Anisimova goes on to face fellow unseeded player Aliaksandra Sasnovich for the title, after the Belarusian beat American Ann Li 7-6 (7-4) 2-6 6-3.

Naomi Osaka will be hoping to be fit for the Australian Open after the reigning champion withdrew from the Melbourne Summer Set 1.

Osaka, who won the most recent of her four grand slam titles last year at Melbourne Park, has looked in fine form this week in her first appearances since returning from the break she took from tennis last year.

The top seed beat Alize Cornet, Maryna Zanevska and Andrea Petkovic en route to the semi-finals, but could not compete against Veronika Kudermetova on Saturday, citing an abdominal injury.

Osaka explained that her body had taken a hit from playing such intense matches in consecutive days, and she instead is looking to rest and recover ahead of the first grand slam of the season, which starts on January 17.

"Sad to withdraw due to injury from my match today, my body got a shock from playing back to back intense matches after the break I took," Osaka tweeted.

"Thank you for all the love this past week [Red heart] I’ll try to rest up and I’ll see you soon!"

Osaka's injury has prevented what looked to be an enticing showdown with Simona Halep, who guaranteed a place in a WTA Tour singles final for a 13th successive season by beating Chinese teenager Zheng Qinwen 6-3 6-2.

Halep's first final came in 2010 and she has taken just a week to get back into her stride after an injury-ravaged 2021 season.

The Romanian, a two-time grand slam champion, went into the week ranked at world number 20, her lowest position at the start of a season since 2013.

However, she has now reached at least the semi-final stage in three successive tournaments, and she will fancy her chances against third seed Kudermetova, who is into her third singles final.

Ash Barty set a new personal best for aces in a match as she rifled 17 past Sofia Kenin on the way through to the Adelaide International 1 semi-finals.

Reigning Wimbledon champion Barty won 31 of 32 points on first serve in a ruthless 6-3 6-4 victory over the 2020 Australian Open winner.

It sets up a tantalising last-four clash with Poland's defending champion Iga Swiatek, who is a frequent practice partner for Australian home favourite Barty.

Explaining her stunning serving performance, Barty said: "I think towards the end Sofia was kind of leaning one way or the other, and I was able to kind of get up and hit my spots."

Facing former French Open winner Swiatek will be a major early-season test for the world number one, with the Warsaw-born 20-year-old fending off former grand slam winner Victoria Azarenka 6-3 2-6 6-1 in Friday's quarter-final.

The other semi-final in Adelaide will see Misaki Doi take on Elena Rybakina after both won in three sets to get there, seeing off Kaja Juvan and Shelby Rogers respectively.

Melbourne Park is staging two tournaments this week, and there is the prospect of a starry final in Melbourne Summer Set 1, with Naomi Osaka and Simona Halep both through to the last four.

Top seed Osaka beat experienced German Andrea Petkovic 6-1 7-5, while second seed Halep had to scrap for a 6-2 5-7 6-4 win against Viktorija Golubic of Switzerland.

Osaka took inspiration from Petkovic's fight in the second set of their contest. Quoted on the tournament website, she said: "It was really cool how she didn't give up for any point, so I just felt like I should do the same thing and see what happens."

Halep said her encounter with Golubic had been "really difficult", adding: "I didn't really trust that I can win this match, but I fought to the end, and I'm very proud of this."

Saturday's semi-finals of Melbourne Summer Set 2 will seed Daria Kasatkina take on Amanda Anisimova, while Ann Li plays Aliaksandra Sasnovich.

Ash Barty produced an impressive comeback to defeat Coco Gauff in her first singles match since the US Open.

World number one Barty moved into the quarter-finals of the Adelaide International with a battling 4-6 7-5 6-1 triumph.

The home hope, who is favourite to win the Australian Open when it starts later this month, was a set and a break down against the American wonderkid before ultimately progressing in two hours and 12 minutes.

Exhausted after a six-month road trip that included Wimbledon glory last year, Barty took a break from the WTA Tour after her third-round exit at Flushing Meadows on September 5.

Her return came in a marquee matchup at the WTA 500 event which did not disappoint, as Barty battled to win 11 of the last 13 games and prevail.

The victor stemmed the early errors she was making on the forehand side, with Gauff paying the price for only converting three of her 15 break-point opportunities. 

It was only the second meeting between Barty and Gauff, with the Australian having to retire with an arm injury while leading their first encounter in Rome last year.

"I felt like I played a pretty good quality match considering it was my first match in a few months," said Barty.

"In the first set I was able to create opportunities but just was a little bit slack on the execution, rusty in the sense of stringing quality points together.

"Midway through the second set I was able to find my rhythm a little bit better on serve and just continued to be aggressive on my forehand. I just found execution a little bit more.

"Coco played great and forced me to hit a lot of balls. I felt I got better and better as the match went on. It was nice to get some court time."

An intriguing last-eight tie lies in wait for Barty. She will either play former Australian Open champion Sofia Kenin or compatriot Ajla Tomljanovic.

And there was more good news for Barty as two of her main rivals for glory were eliminated.

Second seed Aryna Sabalenka was surprisingly beaten as Kaja Juvan, the world number 100, prevailed 7-6 (8-6) 6-1.

Maria Sakkari, the third seed, also crashed out, beaten in three sets by Shelby Rogers, the player who knocked Barty out of the US Open the last time the Australian was on court.

There are two other tournaments taking place this week, both at WTA 250 level.

At Melbourne Summer Set 1, second seed Simona Halep joined Naomi Osaka in round two with a routine 6-4 6-2 win over Destanee Aiava.

The field is not as strong at Melbourne Summer Set 2, where the highest seed remaining, Daria Kasatkina, progressed after opponent Anna Kalinskaya, having already lost the first set, withdrew through injury.

Naomi Osaka marked her return to tennis with a hard-fought win in Melbourne and declared her love for competing had been reignited during a break from the sport.

The former world number one beat French player Alize Cornet 6-4 3-6 6-3 on Tuesday, in her first match since a third-round US Open defeat to eventual runner-up Leylah Fernandez.

The Japanese star said after that Flushing Meadows loss in September that she would put her tennis career on hold indefinitely.

Across several months, Osaka has adjusted her personal and professional priorities, pointing to the joy of San Francisco sleepovers with friends and reconnecting with normal life.

She believes there is a way to focus on the joy of competing, rather than the strains of performing in the public eye that caused her so much consternation last season, and there were glimpses of Osaka's best in the win over world number 61 Cornet at the WTA 250 Melbourne Summer Set 1 tournament.

Osaka pulled out of the 2021 French Open after one match and then elected not to play Wimbledon, as she addressed the importance of protecting her mental health.

She was reluctant to take part in media conferences, finding them harrowing at times, but on Tuesday the 24-year-old embraced the stage and explained how she had surprised herself by coming back to the court so soon.

"I actually really thought I wasn't going to play for most of this year," Osaka said. "I'm really happy with myself that I love the sport that much because I literally said that I was unsure when I was going to play after the US Open and I'm here right now.

"In the break I was feeling like I didn't know what my future was going to be. I'm pretty sure a lot of people can relate to that. Of course, you never know what the future holds, but it was definitely an indecisive time. But I'm really happy to be sitting here right now."

Osaka had envisaged a spell of globe-trotting – without a tennis racquet in her luggage – but the pandemic left her wary of following that route.

In the end, she settled on enjoying a quiet life for a while, saying: "I kind of stayed at home. My friends live near San Francisco, so I was driving to go see them and stay over at their house and bother them quite a few times.

"I feel like that's also an experience that I haven't been able to have in my life, just based on the fact that I play tennis and I travel a lot and I haven't been able to have sleepovers and stuff like that. It was cool to be able to do that."

Osaka said she has just "one major goal for 2022".

"For me, I just want to feel like every time I step on the court I'm having fun," she said. "I can walk off the court knowing that even if I lost, I tried as hard as I could. Also, I have a goal in the press room, that I'm never going to cry again, so hopefully that works out in my favour.

"I'm the type of person that cared a little bit too much about the results and the ranking and stuff like that, and I just need to find a way to enjoy the game again. Because that's the reason why I was playing in the first place."

Quoted on the WTA website, Osaka said opening up to others about the tribulations of life on the circuit helped her to adjust her goals.

"During the off-season I just hung out with my friends and talked to my family a lot. I felt like that was a way of decompressing the pressure I had on myself. Then I just slowly started to regain the feeling of love that I had towards the game," she said. "It's not like it ever completely went away, but I felt like it got overshadowed by a lot of emotions that I was feeling just by constantly playing year after year. Sometimes it's just good to remember why you're playing and stuff."

Top seed Osaka's win came on Rod Laver Arena, the main show court at the Melbourne Park complex that will stage the Australian Open later this month, when Osaka will be defending her title. Fellow seeds Liudmila Samsonova, Bernarda Pera and Alison Riske were beaten.

At the concurrent Melbourne Summer Set 2 event, American top seed Jessica Pegula was ousted in the first round by Romanian Irina-Camelia Begu, losing 7-6 (8-6) 6-3.

The Adelaide International 1 event contains the strongest field this week, and Tuesday saw straight-sets wins for Coco Gauff and a pair of 2020 grand slam winners in Iga Swiatek and Sofia Kenin.

Eighth seed Elina Svitolina had a bad day though, the Ukrainian losing 5-7 6-4 6-3 to Russia's world number 130 Anastasia Gasanova.

Petra Kvitova was on the receiving end of an upset in the first round of the WTA International in Adelaide as she was surprisingly beaten by wildcard Priscilla Hon on Monday.

Two-time Wimbledon champion Kvitova, who ended 2021 among the world's top 20 players for the first time since 2016, lost in three sets to her Australian opponent 6-7 (4-7) 7-5 6-2. The victory was Hon's first ever against a player in the top 40.

Elsewhere, number three seed Maria Sakkari saw off Slovenia's Tamara Zidansek 6-2 0-6 6-4, while number seven seed Elena Rybakina earned a 6-4 1-6 6-1 win over Storm Sanders.

Leylah Fernandez, the 2021 US Open runner-up, also looked comfortable in a straight-sets victory against Ekaterina Alexandrova, easing past the Russian 6-3 6-4. The 19-year-old will face either number five seed Iga Swiatek or Daria Saville in the next round.

Heather Watson is out after a 6-4 7-6 (7-5) loss to home favourite Ajla Tomljanovic, while in the doubles event, Japanese pair and top seeds Ena Shibahara and Shuko Aoyama were beaten 6-4 6-2 by Victoria Azarenka and Paula Badosa, who will play against one another in the singles on Tuesday.

Tokyo Olympics gold medalist Belinda Bencic has tested positive for COVID-19 ahead of next month's Australian Open and is experiencing "severe" symptoms.

World number 23 Bencic returned a positive test, along with Ons Jabeur, after competing at the Mubadala World Tennis Championship in Abu Dhabi.

The pair are the third and fourth players to have tested positive after travelling to the Abu Dhabi event, following 2021 US Open winner Emma Raducanu and 20-time major winner Rafael Nadal.

Bencic wrote on Twitter: "Unfortunately and even though I am fully vaccinated, I recently tested positive for Covid-19.

"I am currently isolating and taking all precautionary [measures] to get through this as best as possible as I am experiencing quite severe symptoms (fever, aches, chills)."

The Mubadala World Tennis Championship typically serves as a warm-up event prior to the Australian Open which is due to begin on January 17 in Melbourne.

World number 10 Jabeur, who defeated Bencic in Abu Dhabi, is experiencing "strong symptoms" and isolating in her native Tunisia.