Daniil Medvedev and Andrey Rublev produced ruthless performances as Russia cruised into the ATP Cup semi-finals.

Russia followed up their day-one win over Argentina with victory against Japan to ensure they will finish top of Group D.

Rublev got things rolling with an emphatic 6-1 6-3 win over Yoshihito Nishioka and Medvedev dispatched Kei Nishikori in a 6-2 6-4 triumph.

Those results meant the subsequent doubles match – which Japan won – would not be relevant.

"I am really happy for the team," said ATP Finals champion Medvedev, who has now won 12 matches in a row on the tour.

"Reaching the semi-finals is a big step – I am really happy that we made it in both singles. Both matches were straight sets, so really happy for the team and hopefully we can go further than that."

Italy, who had beaten Austria on the opening day, are also through after Fabio Fognini and Matteo Berrettini earned wins in straight sets over France duo Benoit Paire and Gael Monfils on Wednesday.

France play Austria next but neither team can catch Italy in Group C.

Alexander Zverev won a thriller against Denis Shapovalov 6-7 (5-7) 6-3 7-6 (7-4) to ensure Germany defeated Canada.

It was a first win at the ATP Cup for US Open runner up Zverev, who had a miserable tournament in 2020.

That sets up a day three contest for Germany against Novak Djokovic and Serbia where the winning team will progress to face Russia.

KYRGIOS AND WAWRINKA THROUGH

Nick Kyrgios – playing his first tournament for a year – made it two wins from two at the Murray River Open, defeating fellow Australian Harry Bourchier 6-2 7-6 (9-7).

First seed Stan Wawrinka survived a scare before prevailing against Mikhail Kukushkin to win 4-6 6-3 6-1 in just under two hours.

Wawrinka will take on Alex Bolt in the last 16, while Kyrgios should be tested against fourth seed Borna Coric.

At the Great Ocean Road Open, top seed David Goffin crashed out as world number 146 Carlos Alcaraz celebrated a shock 6-3 6-3 victory.

Karen Khachanov and Jannik Sinner were among the seeds who progressed, both winning without dropping a set.

Serena Williams roared into the quarter-finals of the Yarra Valley Classic with a 6-1 6-4 victory over Tsvetana Pironkova on a star-studded day of action in Australia.

The 23-time grand slam champion was in fine form at Melbourne Park, where the biggest names in women's tennis were competing across multiple tournaments, as she sealed a straight-sets triumph to continue her preparations for a shot at an eighth Australian Open title.

In doing so the 39-year-old extended her head-to-head record over the Bulgarian to 6-0 and was delighted to get the job done.

"It's definitely nice to get another win," the American said during her on-court interview.

"She's clearly a great player, so it wasn't easy, but it was good to come through."

Speaking at her media conference, Williams added: "Last time it was an incredible three-set match, so today I was like, 'All right, let's really try and focus and learn to do better than last time.'"

World number one Ash Barty had a less straightforward path to the last eight, requiring three sets to see off Marie Bouzkova.

The home hope ultimately prevailed 6-0 4-6 6-3, with second seed and reigning Australian Open champion Sofia Kenin also taken the distance in a 5-7 7-5 6-2 win over Jessica Pegula, as Nadia Podoroska dug deep to down Petra Kvitova 5-7 6-1 7-6 (9-7).

With Barty now set to face Shelby Rogers, Danielle Collins awaits Williams having impressively defeated third seed Karolina Pliskova 7-6 (7-5) 7-6 (7-3), while Garbine Muguruza overcame Anastasia Pavlyuchenkova 6-1 6-2 to set up a meeting with Kenin.

In the Gippsland Trophy, the top three seeds all dodged upsets, with two-time grand slam winner Simona Halep, 2019 Australian Open victor Naomi Osaka and 2018 Tour Finals champion Elina Svitolina safely navigating through the last 16.

Fifth-seeded Briton Johanna Konta failed to convert two match points as she succumbed to a 4-6 7-6 (12-10) 7-6 (7-4) defeat to Irina-Camelia Begu.

Meanwhile, at the Grampians Trophy there were wins for Anett Kontaveit, Jennifer Brady and Angelique Kerber.

World number one Ash Barty won her first WTA Tour match in almost a year at the Yarra Valley Classic, while Naomi Osaka got her Gippsland Trophy campaign going with a victory.

Barty sat out the vast majority of the 2020 season due to the coronavirus pandemic but marked her comeback with a 6-3 6-3 success over Ana Bogdan at Melbourne Park.

The Australian will face Marie Bouzkova next after the Czech defeated Aliona Bolsova on Tuesday.

Garbine Muguruza raced past Alison Van Uytvanck 6-2 6-0 and she was joined in the third round by Petra Kvitova, who battled to beat Venus Williams 7-6 (8-6) 7-5.

Reigning Australian Open champion Sofia Kenin, who was 7-5 up when Camila Giorgi retired from their match, is also through.

In her first match since winning the US Open in September, Osaka cruised to a 6-2 6-2 success against Alize Cornet and will meet Katie Boulter after the Briton came from a set down to beat Coco Gauff 3-6 7-5 6-2.

Iga Swiatek was also making her first appearance since winning a major title – the French Open last October – and after a slow start won 10 of the final 11 games to beat Kaja Juvan 2-6 6-2 6-1.

Aryna Sabalenka ended 2020 with back-to-back titles in Ostrava and Linz, before kicking off the new year with another trophy in Abu Dhabi. However, her run of 15 straight victories ended with a 1-6 6-2 1-6 loss to Kaia Kanepi.

Bianca Andreescu was due to gear up for the Australian Open by contesting the Grampians Trophy this week but withdrew from the competition to focus on training instead.

Novak Djokovic continued his perfect record at the ATP Cup to help Serbia beat Canada in their opening tie.

The world number one won all eight of his rubbers in the 2020 tournament and made a fine start to this event by battling to a 7-5 7-5 win over Denis Shapovalov in Melbourne.

Milos Raonic had earlier put Canada in front when he beat Dusan Lajovic 6-3 6-4, meaning Djokovic had to return for a decisive doubles clash alongside Filip Krajinovic. 

The Serbians prevailed, winning 7-5 7-6 (7-4) against Shapovalov and Raonic.

"Filip Krajinovic was the key," Djokovic said after the doubles triumph extended his undefeated run to 10. 

"The way he played is phenomenal. He came out with very solid returning. He found his serve, great rhythm. He just played some really key shots in the second set when we needed it the most."

Of his singles win, Djokovic added: "It was a very close match. Playing Shapo is always a great challenge on hard courts. 

"He's such a dynamic, explosive player; very talented. I thought we played on a very high level, so I'm really pleased with how I've started the season.

"This is the best way to kickstart the season, playing for your country.

"We don't get to see crowds in the tennis stadiums these days so much, so it's definitely a blessing. I'm really grateful to see you guys here in the stands."

SPAIN WIN WITHOUT NADAL

Defending champions Spain were without Rafael Nadal for their tie against Australia, but they still prevailed.

Pablo Carreno Busta had few problems seeing off John Millman 6-2 6-4.

And Roberto Bautista Agut ensured the tie was won before the doubles by emerging triumphant in an entertaining encounter with Alex de Minaur, which the Spaniard won 4-6 6-4 6-4.

Nadal, who is battling a back problem, hopes to return on Thursday when Spain take on Greece.

Elsewhere, Austria fell to a 2-1 loss against Italy, as US Open champion Dominic Thiem struggled.

After team-mate Dennis Novak had superbly beaten Fabio Fognini, world number three Thiem fell to a surprise 6-2 6-4 loss against Matteo Berrettini, with Austria going on to lose the decisive doubles.

Andrey Rublev and Daniil Medvedev beat Guido Pella and Diego Schwartzman respectively as Russia produced an impressive performance to beat Argentina.

Elsewhere, at the Murray River Open, Nick Kyrgios made a winning start to his comeback after a year out of action.

He did not have it easy against the unheralded Frenchman Alexandre Muller, but salvaged a 3-6 6-4 7-6 (7-4) victory to book a second-round meeting with fellow Australian Harry Bourchier.

Roger Federer is aiming to make his return to the ATP Tour at the Qatar Open, while Rafael Nadal is contending with a back injury with less than a week until the Australian Open.

Swiss maestro Federer has not played since losing in the semi-finals at Melbourne Park to Novak Djokovic in 2020 having undergone knee surgery last year.

The 20-time grand slam champion opted not to play in Australia this year but is aiming to return in Doha in March.

"I want to celebrate great victories again. And for that I am ready to go the long, hard road," Federer, a three-time champion at the tournament, said in an interview with SRF.

"I wanted to make my comeback at a smaller tournament so that I wasn't fully in focus and where the stress is also a little less."

Federer said it "hurts" to miss out in Australia but still has lofty ambitions at Wimbledon, the Olympics and the US Open in 2021, while saying he will attempt to play on clay this year.

"I'll try to play on clay again. The whole thing, of course, with regards to Halle, Wimbledon, the Olympics and the US Open," he added.

Federer's on-court rival Nadal matched the Swiss for most grand slam singles titles won by a male player after winning the French Open last year.

But his chances of going one better may be hindered by a back issue that forced the Spanish great to sit out his country's ATP Cup opener against Stefanos Tsitsipas on Tuesday.

"Hi all, we have decided with #TeamSpain and my team, to not play today the first match of the @ATPCup here in #Melbourne since I have a stiff low back. Hopefully I'll be better for Thursday," Nadal posted on Twitter.

Serena Williams and Simona Halep started the season with straight-sets victories in Melbourne a week before the Australian Open gets under way.

Williams and Halep played in an exhibition event with a crowd of 4,000 watching on in Adelaide last Friday and they were back in competitive action three days later.

Legendary American Williams beat Daria Gavrilova 6-1 6-4 to move into the third round of the Yarra Valley Classic.

The fifth seed struck 27 winners to 15 unforced errors on Margaret Court Arena as she set up a meeting with Tsvetana Pironkova, who ousted Donna Vekic 1-6 6-4 6-2.

Williams said: "It was a good match for me. It wasn't easy at all. It was lots of rallies and lots of movement, and she's from here, so she obviously always plays hard. So it was really good and it felt good to clinch that in the end."

Third seed Karolina Pliskova, Petra Martic, Danielle Collins and Marketa Vondrousova also advanced to the last 16 on Monday.

Elsewhere, top seed Halep is through to the third round of the Gippsland Trophy following a 6-4 6-4 win over Anastasia Potapova.

Halep hit 23 winners and broke twice in each set in what was her first official match since October.

Elina Svitolina, the third seed, beat Andrea Petkovic 6-1 6-4, while Coco Gauff, Ekaterina Alexandrova and Jelena Ostapenko were among the other winners seven days prior to the start of the first grand slam of 2021.

Rafael Nadal wants to play at the Olympics but the star said fitting more quarantining into the ATP Tour calendar looked "difficult".

After being postponed last year due to the coronavirus pandemic, the Games are scheduled to start in Tokyo on July 23.

Naomi Osaka said she would be willing to quarantine ahead of the Olympics, with players having gone through similar in preparation for the Australian Open.

Nadal, an Olympic gold medallist in singles and doubles in 2008 and 2016 respectively, said he would listen to the experts, but acknowledged quarantining could be tough.

"It's the same as always. I am nobody to have a clear opinion on that.  I am just a tennis player, a human person that doesn't have enough knowledge about all the situation," the Spanish star told a news conference on Sunday.

"What we have to do is just follow the instructions of what the people who really have the right knowledge of all this stuff give to us. What's going to happen in Tokyo for the Olympics, if the Olympics are going to happen or not, or if we have to do quarantine before Olympics for 15 days or not, seems like a sports perspective very difficult because it's difficult for us, I don't know, combining our Tour with another 15 days of quarantine to play Olympics. It looks difficult to fix it in our calendar.

"But, as I said, we're going to do what the people who know about virus and who know about protecting the people in every single country, [we] are going to just follow their instructions."

Asked if his intention was to go, Nadal said: "I think everybody wants to play in Olympic Games, then let's see what's going on."

Nadal and Spain will begin their ATP Cup campaign against Australia on Tuesday.

Naomi Osaka would be prepared to spend another two weeks in quarantine to be able to play at a "very special" Olympics in Tokyo.

Postponed due to the coronavirus pandemic, the Games are scheduled to begin on July 23 this year.

This year's Australian Open will begin on February 8 after players quarantined ahead of the first grand slam of the year.

Osaka said she would be prepared to do it all again if it meant she got the chance to play at the Olympics.

"Honestly, my concern isn't the athletes. The way that I feel is I will stay in my room for two weeks to play the Olympics. I missed out on the last one," the Japanese star told a news conference on Sunday.

"Playing in Tokyo would be very special to me. My concern would be the general safety of everyone else because you're opening the country.  Everyone is flying in from different places. I would just want the public to feel safe.

"I feel like the athletes definitely would want to play, but I would want the public to feel safe."

Doubts have also been cast over the Olympics going ahead this year due to COVID-19.

Osaka, a three-time major champion, said while people she had spoken to were excited, some were worried.

"For me the people that I've spoken to, they're really excited about it, but they're concerned because, I don't know, there's just like so many different people entering. I don't know," she said.

"For the people I've talked to, they said as long as everyone is safe, as long as Japan is getting better and not worse, then it should be okay.

"But for me, hmm, don't quote me on that."

Ahead of the Australian Open, Osaka is playing the Gippsland Trophy, where she will face either Alize Cornet or Ajla Tomljanovic in the second round.

The Australian Open is set to welcome up to 30,000 spectators each day when the tournament begins on February 8 in Melbourne.

Local officials have given the go-ahead for fans to head to Melbourne Park, predicting a near-normal atmosphere when action begins at the year's first grand slam.

Last year's US Open was contested behind closed doors in New York, while only 1,000 paying fans were allowed at Roland Garros on each day of the 2020 French Open.

However, the COVID-19 crisis has been tightly managed in Australia, to the point where it was reported on Saturday that there had been no new local cases in the state of Victoria for 24 days.

The crowds will be split between day and evening sessions, and the number of fans allowed will drop to 25,000 for the final six days of the tournament, when fewer courts will be in operation.

Saturday's announcement means the event will be capped at around 50 per cent of capacity.

Tournament director and Tennis Australia chief executive officer Craig Tiley said it had taken "a massive team effort" to accommodate the arrival of around 1,000 players and officials into the country, with all required to spend two weeks in quarantine.

Victoria sports minister Martin Pakula said on Sky News Australia: "On Rod Laver Arena, as we get towards the end of the tournament, we'll have an incredible atmosphere – not that different to the atmosphere we've seen in all the Opens in the years past.

"That's really a testament to the work Victorians have done to get our numbers to zero but also the extraordinary work that Craig and the team at Tennis Australia has done."

Serena Williams and Rafael Nadal agreed it was great to be playing in front of busy grandstands again as tennis stars emerged from lockdown in Australia.

The women's and men's tennis tours have been contested largely behind closed doors over the past year, and a number of tournaments, most notably Wimbledon, have been cancelled due to the COVID-19 crisis.

The Australia public has given a cautious welcome to the arrival of the world's leading players, who have been quarantining in hotel rooms for much of the past fortnight, only allowed to briefly leave in order to train.

Ahead of the Australian Open, which begins on February 8 in Melbourne, Williams and Nadal are among a star-studded set of players who travelled to Adelaide to feature in the 'A Day at the Drive' exhibition event.

They both scored victories on Friday, with Williams defeating US Open champion Naomi Osaka 6-2 2-6 10-7 and Nadal snatching a 7-5 6-4 win over Dominic Thiem.

The delight in both at seeing crowds at a tournament was plain, with Williams saying in an on-court interview: "Thanks everyone for having us. We haven't played in front of a crowd in over a year. It's been a really long time."

In fact, it has not quite been a full year since the tours locked down initially, as it was early March when most tournaments began to be called off, with crowds frozen out.

Williams said the reception made the difficult past fortnight, being hidden away from the world, worth the strain for the players.

"This is really cool and then for having us and trusting us with your laws was great," said the 23-time grand slam winner. "We were so excited to be here and it's worth it."

Nadal said he was "super happy" to still be playing at the highest level and back in front of Australian crowds.

The pandemic has been carefully managed to the point where very few have the virus and it is considered safe to allow crowds into sporting events in the country.

Nadal said: "Hopefully this situation will go away quick and we will be able to enjoy fans on court [around the world].

"We're super excited to have fans at the Australian Open and today."

That optimism and excitement was shared by men's world number one Novak Djokovic, who played just one set against Jannik Sinner due to a problem with blisters on his right hand.

Eight-time Australian Open champion Djokovic told fans: "Thank you so much for coming out and making our day and making our year.

"We didn't play in front of this much crowd for 12 months. This is definitely something very special.

"It wasn't easy, obviously, with 14 days being constrained in the room and a few hours to train, but at the end of the day it was worth it because you guys made it very special today for us."

Novak Djokovic apologised but confirmed he had been dealing with a blister after only playing a set of his exhibition match in Adelaide.

The world number one had reportedly withdrawn and was replaced by Filip Krajinovic for a clash against Jannik Sinner.

But Djokovic played the second set, winning it 6-3 after Krajinovic had taken the opener 6-3 on Friday.

The 17-time grand slam champion, who had a blister on his right hand, apologised after the match.

"I'm sorry that I didn't step in on the court from the beginning," Djokovic told Channel 9.

"I had to do some treatment with my physio and wasn't feeling my best the last couple of days, I didn't know how I'm going to react.

"I wanted to play and I wanted to get out here and hopefully it was enough for you guys to see all three of us performing in front of you on the court today, I hope you enjoyed."

Djokovic, who came out of hotel quarantine on Friday, said he could not pass up the opportunity to play in front of fans.

"It's not easy but it's part of what we do. We are professional athletes we learn over the years to play with the pain and it's just a question and case whether that pain is bearable or not," he said.

"Obviously coming off from the hard training block and having an ATP Cup and Australian Open around the corner you don't want to risk it too much.

"But the emotion was so strong in me to come out on the court today seeing almost full stands, I had to play, that's it, I had to play."

Djokovic is due to play the ATP Cup starting on Tuesday, before the Australian Open begins on February 8.

Andy Murray has withdrawn from the Australian Open a little over a week after testing positive for coronavirus.

Murray, a five-time finalist in Melbourne, went into isolation at home after returning a positive test on January 14.

The three-time major winner, ranked 123rd in the world, had hoped to compete at the first grand slam of the year after being granted a wildcard.

However, tournament organisers indicated it would be difficult for Murray to remain in the draw as he would be unable to travel via one of the official charter flights containing other players before going through the required period of quarantine.

On Friday, the 33-year-old confirmed he had been unable to come to a "workable" solution with authorities.

In a statement carried by The Guardian and other UK media outlets, Murray said: "Gutted to share that I won't be flying out to Australia to compete at the Australian Open.

"We've been in constant dialogue with Tennis Australia to try and find a solution but we couldn't make it work.

"I want to thank everyone there for their efforts, I'm devastated not to be playing out in Australia. It's a country and tournament that I love."

The build-up to this year's Australian Open has been impacted by players having to spend a two-week quarantine in their hotel accommodation.

A total of 72 competitors have been unable to leave their rooms after positive coronavirus tests among passengers on the chartered flights to Melbourne.

Players have been unable to access practice courts and many have complained on social media about sub-standard food and conditions, with Yulia Putintseva, the world number 28, sharing videos showing mice in her room.

The tournament is due to start on February 8.

Tennis umpire Carlos Bernardes is "recovering well" after reportedly suffering a heart attack ahead of the Australian Open.

The veteran Brazilian, who has officiated in US Open and Wimbledon men's singles finals, was taken from his hotel to a Melbourne hospital on Wednesday after falling ill.

It was widely reported he had a heart attack, with Bernardes pictured on a stretcher while being loaded into an ambulance.

The ATP, which runs the men's tour and has been Bernardes' employer since 1990, offered an positive update on Thursday.

In a statement, the governing body said: "Following admittance to hospital [non-COVID related] on Wednesday in Melbourne, we are pleased to report that ATP umpire Carlos Bernardes is recovering well.

"Carlos passes on his gratitude for all the well wishes he's received, and we wish him all the best for a full recovery."

According to Brazilian tennis website TenisNews, Bernardes remains under observation but is expected to leave hospital on Saturday.

He was staying at The View, one of three hotels where Australian Open players and tennis officials are quarantining for two weeks after their arrival in the country.

Novak Djokovic has denied he was being "selfish, difficult and ungrateful" in making suggestions for easing quarantine restrictions ahead of the Australian Open.

Djokovic came in for criticism after it emerged he had sent Australian Open tournament director Craig Tiley a list of potential ways for lockdown conditions to be improved for players who are under a strict lockdown in Melbourne.

Less than three weeks before the first major of the year gets under way, 72 players are consigned to their hotel rooms due to positive coronavirus tests on their flights to Melbourne.

World number one Djokovic does not have to adhere to such stringent rules in Adelaide, as he arrived on a virus-free flight.

The 17-time grand slam champion was labelled a "tool" by Nick Kyrgios after he was said to have asked for less time in isolation for players, requested they are given private housing with access to training courts, and better food.

Djokovic responded on Wednesday by stating that he was only trying to look out for his fellow players and expressed his gratitude to tournament organisers, the Australian government and the people of Melbourne.

He posted on social media: "My good intentions for my fellow competitors in Melbourne have been misconstrued as being selfish, difficult and ungrateful. This couldn't be farther from the truth

"I genuinely care about my fellow players and I also understand very well how the world is run and who gets bigger and better and why.

"I've earned my privileges the hard way and for that reason it is very difficult for me to be a mere onlooker knowing how much every help, gesture and good word mattered to me when I was small and insignificant in the world pecking order.

"Hence I use my position of privilege to be of service as much as I can where and when needed."

The Serb added of his correspondence with Tiley: "In our email exchange I used an opportunity to brainstorm about potential improvements that could be made to the quarantine of players in Melbourne that were in full lockdown.

"There were a few suggestions and ideas that I gathered from other players from our chat group and there was no harm intended to try and help.

"I was aware that the chances were low that any of our suggestions would be accepted, just like my request to quarantine with my team in Melbourne instead of Adelaide was denied prior to our travel because of the strict government regulations.

"I understand that organising international sporting events during a pandemic poses health risks to the local community and to the players themselves.

"Therefore, I would like to express my full gratitude to Tennis Australia, the Australian Government and local citizens for being willing to take this risk with us for the love of the game and the multiple opportunities it brings to the economy of the country and its people.

"We are honoured and we will all do our best to follow the guidelines and protocols put in place. We do hope that we will be able to nurture our bodies and be ready for the mental and physical endurance and strength tests that are ahead of us once the competition starts.

"Things in the media escalated and there was a general impression that the players [including myself] are ungrateful, weak and selfish because of their unpleasant feelings in quarantine. I am very sorry that it has come that because I do know how grateful many are.

"We all came to Australia to compete. Not being able to train and prepare before the tournament starts is really not easy. None of us ever questioned 14 days of quarantine despite what is being said by media outlets."

Victoria Azarenka called for greater understanding from players stuck in hotel quarantine ahead of the Australian Open.

After being exposed to coronavirus on flights, 72 players – including Azarenka – have been forced into a two-week quarantine ahead of the tournament beginning on February 8.

Novak Djokovic reportedly made several requests, which were rejected, of officials for players in quarantine, while Roberto Bautista Agut compared the conditions to prison.

But amid complaints on social media, two-time Australian Open champion Azarenka pleaded for players to be more understanding in a measured statement.

"Dear players, coaches, entourage and Australian community. I would like to take a moment and address some of my colleagues as well as the media around the world," the Belarusian wrote on Twitter.

"This has been a very difficult time for a lot of us that did not expect to end up in the situation we are in today, myself included. To be in a 14-day hard quarantine is very tough to accept in terms of all the work that everyone has been putting in during their off-season – to be prepared for playing our first grand slam of the year. I understand all the frustration and feeling of unfairness that has been coming and it is overwhelming.

"We have a global pandemic, nobody has a clear playbook of how to operate at full capacity and without a glitch, we all have seen it last year. Sometimes things happen and we need to accept, adapt and keep moving.

"I would like to ask all my colleagues for cooperation, understanding and empathy for the local community that has been going through a lot of very demanding restrictions that they did not choose, but were forced to follow.

"I would like to ask to be sensitive as well to the people who have lost their jobs and loved ones during this horrible time for all of us around the world. I would like to ask all of us to have respect for people who work tirelessly to try to make our lives easier.

"I would like to ask the media to please have consciousness on the impact and influence you bring to this situation and to the community. I would like for the people in the community to know and understand that we have it as our top priority to ensure the health [and] safety of all the people.

"Lastly, I would like for us to please try to support each other as much as someone can or is willing to. Things are always easier when you have a compassionate environment and work together."

Victoria endured tough restrictions after a second coronavirus wave last year.

On Tuesday, the state recorded its 13th consecutive day of no locally acquired cases of COVID-19.