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."

Dominic Thiem's bid to reach back-to-back Australian Open finals was dashed by Grigor Dimitrov as the US Open champion surprisingly crashed out in the round of 16.

Thiem lost a thrilling final to Novak Djokovic in last year's Melbourne Park decider before breaking through for his maiden grand slam title at Flushing Meadows later in 2020.

But Thiem failed to secure another second-week berth in Melbourne, where the third seed was stunned 6-4 6-4 6-0 by former world number three Dimitrov on Sunday.

Thiem was aiming to reach the Australian Open quarter-finals for the second time and become the second Austrian man to feature in the quarters in Melbourne on multiple occasions after Thomas Muster (1989, 1994 and 1997).

The 27-year-old Thiem was also bidding to reach his ninth slam quarter-final and equal Muster's record for most major last-eight appearances by any Austrian – male or female.

However, Thiem – who rallied from two-sets-to-love down to top Nick Kyrgios in the previous round – was no match for Dimitrov behind closed doors on Rod Laver Arena amid a coronavirus lockdown in Victoria.

Both players hit 25 winners, but Dimitrov only tallied 18 unforced errors to Thiem's 41 following just over two hours on court.

Dimitrov progressed to his fourth Australian Open quarter-final, extending his record for most last-eight appearances at Melbourne Park by a Bulgarian player – man or woman.

An Australian Open semi-finalist in 2017, Dimitrov will now contest his sixth grand slam quarter-final – the 29-year-old is third for most quarter-final appearances by a Bulgarian player, behind Manuela Maleeva (nine) and Katerina Maleeva (seven).

Rafael Nadal was able to offer a positive update on his fitness after easing into the second week at the Australian Open.

The 20-time grand slam champion is playing in his first tournament since November's ATP Finals and faced a battle to make the Melbourne major due to a back problem.

But Nadal has made the fourth round without dropping a set, seeing off Cameron Norrie 7-5 6-2 7-5 on Saturday.

"I did things well, [then there are] things that I need to improve. Something normal," the Spaniard said. "But, yes, happy, of course. Second week, straight sets. Can't complain."
 

PAIN RELIEF AT LAST FOR RAFA

Nadal might have been similarly dominant in his prior matches but revealed after beating Norrie he is only now feeling fitter.

"No, the back was not getting better each day; it was getting better today," he said. "But today is better, yeah, the first day I feel an improvement, and that's the most important thing for me today, more than any other thing.

"Of course, I was not serving my normal serve for the last 15 days. Today is the first day that I started to serve again my normal serve.

"But yesterday I didn't practice, so today was just warming up with the new, normal movement.

"So, of course, I didn't serve bad, but I can do better, I think. And I'm looking forward to doing it better. It has been an important victory for me.

"The biggest victory is the back is better for the first day. That's the most important thing."

Nadal will face Fabio Fognini next after he ended Australia's interest in the home grand slam with a 6-4 6-3 6-4 victory over Alex De Minaur, the host nation's final hope.

"It's one of those matches," an impressed De Minaur said. "You're out there leaving it all out there, but you can just feel that he's playing at another level."
 

MOODY MEDVEDEV MAKES AMENDS

There are three Russian men in the last 16 for the first time in Melbourne in the Open Era, but the country's biggest name survived a major scare.

Daniil Medvedev was cruising after taking the first two sets against Filip Krajinovic, only to drop the next two and engage in an angry back-and-forth with coach Gilles Cervara.

Cervara eventually left Medvedev's box as the fourth seed trailed 4-1 in the fourth set and did not return, but the 25-year-old recovered to get the job done in dominant fashion, a 6-3 6-3 4-6 3-6 6-0 victor.

Medvedev, with Mackenzie McDonald next, said of the incident with Cervara: "He said just before leaving that he's sure I'm going to win the match, but he's going to leave to let me be more calm.

"Sometimes maybe I will disagree but this time for sure it was a good thing to do.

"Today it helped, and definitely we're going to talk about it a little bit, but there is not a big deal."

Andrey Rublev joined Medvedev and compatriot Aslan Karatsev in the fourth round as he improved to 7-0 for the year with a three-set defeat of Feliciano Lopez. He will play Casper Ruud.
 

HISTORY CHANNEL OVER CHAMP

Defending champion Novak Djokovic's struggles with injury on Friday might have intrigued much of the tennis public, but Stefanos Tsitsipas was not overly concerned.

The fifth seed, who breezed past Mikael Ymer, did not watch the match and revealed he has little interest in keeping up with the exploits of his rivals.

"I might watch [Djokovic and Nadal] a little bit on TV if it happens that the TV is on or the right channel is on," he said. "Otherwise I just switch to History Channel.

"Definitely not tennis history. I think I have enough of tennis being in here every single day."

Tsitsipas will next play Matteo Berrettini, who is enjoying his best run at the Australian Open and saw off a side complaint to advance in three sets by edging Karen Khachanov, another Russian, in a trio of tie-breakers.

Ash Barty may have her focus on winning the Australian Open right now but suggested a career change could be on the cards in the future.  

The world number one made sure she will still be competing during the second week of the tournament in Melbourne by beating Ekaterina Alexandrova in straight sets.  

But, having played international cricket for Australia before switching to tennis, could the multi-talented Barty be considering trying another sport?  

Elsewhere in Saturday's action, Karolina Pliskova lost her cool – and also a couple of rackets – as she slipped to defeat against the impressive Karolina Muchova in an empty Rod Laver Arena, with fans not able to be present due to a five-day lockdown in the state of Victoria.

Elina Svitolina had no such problems in her third-round match, while Elise Mertens was victorious in just over an hour against Belinda Bencic. Jennifer Brady ended Slovenian qualifier Kaja Juvan's run in the first grand slam of the year.

AUSSIE RULES, OK? 

After winning 6-2 6-4 without ever needing to be at her peak, Barty was cheekily asked by former doubles partner Casey Dellacqua – now working in the media – whether she may be set to switch paths again, once her tennis career has come to an end.  

Australian rules football was the answer – but Dellacqua maybe got more than she bargained for from her former playing partner during the on-court interview. 

"I thought it was our deal, we're going to AFLW. It's ABCD [the nickname for the pairing from their doubles career]. We come as a package, and I know we will be going to the [Richmond] Tigers that is for sure," Barty said. "You can't go to Carlton. You have to come to the 'Tiges' with me."

Dellacqua replied: "I need to get out there and start practicing some kicking, but you are good. I would love to do that one day." 

For Barty, though, the next challenge facing her is Shelby Rogers, who knocked out 21st seed Anett Kontaveit during the evening session.  

MAKING A RACKET 

A disgruntled Pliskova was not impressed when punished for smashing up a racket during her match with compatriot Muchova. 

Having received a warning when throwing a racket to the floor during the course of the final game in the opening set, the sixth seed then vented her frustration again on another while in the players' tunnel.  

An official witnessed the incident and reported it to chair umpire Alison Hughes, who punished the Czech with a point penalty before she began serving to open the second set.  

"It's off court, I'm allowed to do what I want," Pliskova insisted when querying the decision to the official. She would go on to hold before recording two successive breaks, yet somehow failed to force a decider.  

Muchova rallied from 5-0 down in sensational fashion, winning seven games on the spin to triumph 7-5 7-5 to make it through to the last 16.

CONTRASTING PROGRESS FOR SEEDS

Svitolina has still yet to drop a set in the tournament after overcoming 26th seed Yulia Putintseva by a 6-4 6-0 scoreline.  

The fifth seed was twice down a break in the first set but, after eventually coming out on top to take a 1-0 lead, breezed through the second in a hurry.  

"She has a very different game style from what I played my last two rounds, so it wasn't easy at the beginning to adjust," Svitolina said. "As soon as I was feeling better, I just stepped my game, and it was quite a comfortable win after." 

Next up will be Jessica Pegula, who is through to the fourth round at a slam for the first time in her career after thrashing Kristina Mladenovic 6-2 6-1.  

There was also success for another American in the main draw, Brady defeating Juvan in straight sets. Her reward is a clash with Donna Vekic, the 28th seed having to save a match point before eventually seeing off Kaia Kanepi 5-7 7-6 (7-2) 6-4 after two hours and 38 minutes on court. 

Rafael Nadal rounded off a comfortable first week at the Australian Open with a straight-sets win over Cameron Norrie to reach the last 16.

The Spaniard triumphed 7-5 6-2 7-5 in two hours and 14 minutes on Rod Laver Arena on Saturday.

Nadal was short of his brilliant best but a third-round victory never looked in doubt from the moment he emerged triumphant from a competitive opening set.

He will face number 16 seed Fabio Fognini, who defeated home favourite Alex de Minaur, in the fourth round.

The world number two will fancy his chances of a first Australian Open title since 2009, especially with defending champion Novak Djokovic struggling with an injury.

Nadal is yet to drop a set or even be taken to a tie-break at the tournament but he almost was by Norrie in the first meeting between the players.

World number 69 Norrie claimed the first break of the match in the fifth game when Nadal found the net with a forehand.

But the 20-time grand slam champion immediately broke back and then pivotally struck again while Norrie was serving to stay in the set at 6-5.

Norrie was unable to force a break point in the match, with Nadal racing clear to break twice and secure the second set.

The Briton saved two break points early in the third set but that was only delaying the inevitable.

It again looked like Norrie would force a tie-break, but once more Nadal struck when it mattered at 6-5, a forehand winner setting up match point that was converted when his opponent sent a backhand wide.

Data Slam: Nadal punishes Norrie second serve

Norrie won only seven of 30 points on his second serve, his 23 per cent win rate falling well short of Nadal in that category (18/26, 69 per cent). The match was competitive apart from the second set, where four winners and 14 unforced errors from Norrie meant Nadal did not need to do much to go two ahead and put the result beyond doubt.

WINNERS/UNFORCED ERRORS
Norrie– 25/43
Nadal– 33/35

ACES/DOUBLE FAULTS
Norrie– 9/4
Nadal– 7/1

BREAK POINTS WON
Norrie– 1/1
Nadal– 5/12

Ash Barty battled back to win both sets against Ekaterina Alexandrova and book a place in the fourth round of the Australian Open. 

The world number one triumphed 6-2 6-4 after one hour and 21 minutes on court, though there was no crowd present to cheer on the home favourite due to the five-day lockdown in place in Victoria. 

Barty admitted that, with fans having been allowed into Melbourne Park earlier in the tournament, there was a different – if not completely unpleasant – atmosphere to proceedings in the evening session on Margaret Court Arena.

"It's very strange, it changes the sound of the court a little bit," the Australian – who played with her left thigh heavily strapped having pulled out of doubles duty on Friday – said during her on-court interview.

"I love the crowd, but I love the sound the ball makes. It feels a bit like practice."

Barty lost her opening service game as she quickly fell 2-0 behind at the start of the contest, though she hit back impressively to take the opener against the 29th seed.

The 2019 French Open champion claimed six successive games, hitting just five winners as the policy of keeping the ball in play paid off thanks to 16 unforced errors from her opponent. 

Alexandrova was more consistent in the second set, leading to a break of serve that she quickly consolidated to make the score 4-2. 

However, the Russian was unable to cling on to her advantage and, when serving to stay in the match, let slip two opportunities to extend proceedings. Barty will next face Shelby Rogers, who knocked out 21st seed Anett Kontaveit in straight sets.

Elina Svitolina said playing behind closed doors at the Australian Open felt "a bit disturbing" after having fans in attendance earlier in the week.

The Ukrainian fifth seed booked her spot in the fourth round in Melbourne with a 6-4 6-0 victory over Yulia Putintseva on Saturday.

But no fans were in attendance on Margaret Court Arena as Victoria started a five-day lockdown due to coronavirus.

Svitolina, who will face Jessica Pegula in the last 16, said she felt the difference.

"It was very different conditions. I played a night match at 7:00 with a good crowd. Now it was completely different. It was for sure a bit disturbing, I would say, in some ways sad," she told a news conference.

"But it is what it is. I had to accept. I had to have a good mindset, not thinking too much about that. I just tried to focus on my game."

Svitolina reached the fourth round in Melbourne for the third time in four years after mixing 18 winners with 20 unforced errors.

But the 26-year-old said the lack of fans meant the third-round encounter felt like a practice match.

"It feels like that. I actually had few thoughts about it today. It feels like this. I tried to convince myself that it's a grand slam and that we are playing an important match. I have to focus on my match," Svitolina said.

"But for sure there's some thoughts and there is I say some low moments that can sneak into the mind. It's what we have to deal with. I'm trying my best to do it."

Novak Djokovic insists there is a real danger he may withdraw from the Australian Open, with an ultrasound on an abdominal injury planned for Saturday.

The eight-time champion at Melbourne Park pulled off a dramatic five-set win over American Taylor Fritz to reach round four, but it came at what could prove a high cost.

After battling through two tight sets to forge ahead in the match, Djokovic was jolted early in the third by a sudden "tear", as he put it.

Although painkillers allowed him to continue and fend off a Fritz comeback, the world number one might be advised by doctors that his race in Australia is run for this year.

He is due to face Milos Raonic on Sunday in round four, and the Canadian is a player that Djokovic holds an 11-0 winning career record against. This time Raonic could be gifted a walkover.

Explaining the injury blow, and what comes next, Djokovic said: "Everything was working fine for me, and then beginning of the third set I made this quick move on the return going to the forehand, rotating there, and I just felt a tear, I felt something happen.

"Went out for medical timeout when I was tested, evaluated. I have huge pain, I took the highest dose of anti-inflammatories possible.

"It did kick in end of fourth, beginning of the fifth when I actually started to move and I could actually start to rally with him from back of the court.

"Until that moment, it was only serve for me and kind of hoping and praying that I'm going to get an easy ball after my serve so I could just go for it. That's what I've done.

"I honestly don't know how I won this match. I'm very proud, at the same time sad and worried, because it's definitely something serious happening with my injury.

"I don't have much time to recover for the next match. Definitely not training tomorrow [Saturday]."

The 33-year-old Serbian would not want to risk worsening the problem, given he has plenty to play for over the rest of the year.

However, he is chasing grand slam success wherever he can get it, given he trails Roger Federer and Rafael Nadal by three on the all-time list.

Djokovic's disqualification for hitting a ball that struck a line judge at the US Open last year was followed by defeat to Nadal in the French Open final, and now his luck may be out again.

Once the tests take place on Saturday, there should be a greater sense of clarity in Djokovic's mind.

Setting the scene for what should have been a relaxed day of practice but is now a crucial day in his championship, Djokovic stressed he hoped to be able to continue.

He said of his Saturday plan: "I'm coming here to evaluate more with the doctor and medical team, and do some ultrasound and understand what's really going on so that the doctor and medical team can prescribe best possible treatment and the only possible treatment that I could even have the slightest chance to go out in less than 48 hours."

Novak Djokovic is unsure whether he will be able to play in the Australian Open fourth round after struggling with an abdominal injury in his five-set win over Taylor Fritz.

The world number one survived a huge injury scare to get past Fritz in the third round, winning 7-6 (7-1) 6-4 3-6 4-6 6-2 on Rod Laver Arena.

Eight-time Australian Open champion Djokovic appeared to injure his abdominal region during the third set.

It was a match which started on Friday in front of a crowd and finished on Saturday without fans as Victoria went into a five-day lockdown.

Fritz appeared set to reach the fourth round of a major for the first time in his career, but Djokovic suddenly came to life in the fifth set.

Next up for Djokovic is Milos Raonic, who he has beaten in all 11 of their meetings, on Sunday.

But the Serbian is concerned by his injury and was unable to commit to saying he would be able to take to the court.

"I really don't know," Djokovic said when asked for his thoughts about facing Raonic.

"Right now, I know it's a tear, definitely, of the muscle so I don't know if I'll manage to recover from that in less than two days.

"I don't know. I don't know. I don't know if I'm going to step out on the court or not.

"I am very proud of this achievement. Let's see what happens."

Djokovic felt for American Fritz after his brave defeat and discussed what he had gone through during a contest lasting three hours and 25 minutes.

He continued: "I want to congratulate Taylor for a great fight. I'm sorry that he lost the match obviously.

"I don't know. I just tried to stay in there and I was hopeful that whatever is happening there is going to feel better.

"Towards the end of the fourth it started to feel better, third and fourth set I just served and couldn't do much on the return.

"I was just going for my shots, was hitting two first serves and it worked, it worked well.

"This is definitely one of the more special wins in my life. It doesn't matter what round it is and against who it is.

"Under these kinds of circumstances, to pull this through is definitely something I'll remember forever."

Novak Djokovic survived a huge injury scare to get past Taylor Fritz in the Australian Open third round - but his title defence could be in ruins.

The world number one and eight-time champion in Melbourne edged Fritz 7-6 (7-1) 6-4 3-6 4-6 6-2 on Rod Laver Arena.

But the 17-time grand slam winner appeared to injure his abdominal region during the third set of the contest, which started on Friday in front of a crowd and finished on Saturday without fans as Victoria went into a five-day lockdown due to coronavirus concerns.

Fritz appeared set to reach the fourth round for the first time in his major career, but Djokovic suddenly came to life in the fifth set.

Next up for Djokovic is Milos Raonic, who he has beaten in all 11 of their meetings, but whether the Serbian is fit enough to play remains to be seen.

Djokovic told Eurosport he suspected he had suffered a torn muscle and that it was "in the clouds" whether he would be able to continue in the tournament.

Djokovic broke for 3-1 against Fritz and crucially dug himself out of a 15-40 hole in the seventh game, but a forehand into the net saw him fail to serve out the set.

Yet Djokovic was close to flawless in the tie-break, winning the first six points before closing it out, and then breaking to begin the second set.

That spurred Djokovic to win the second before the drama followed.

He took a medical timeout after the third game of the third set and then repeatedly required treatment on his abdominal region.

The injury seemed to be bothering Djokovic, who was broken after sending a forehand long in the eighth game, and Fritz closed out the set.

A struggling Djokovic was broken again in the third game of the fourth set before fans were forced to leave Rod Laver Arena ahead of restrictions being introduced in Victoria, but Fritz levelled the match.

Djokovic looked far healthier to begin the final set and he broke for 4-2 with a brilliant forehand winner after a baseline exchange, winning four straight games on his way to a post-midnight victory.

Data Slam: Djokovic's American dominance continues … just
Djokovic extended his winning streak against Americans at tour level to 17 matches. His last loss to an American opponent came against Sam Querrey at Wimbledon in 2016.

WINNERS/UNFORCED ERRORS
Djokovic – 52/53
Fritz – 62/45

ACES/DOUBLE FAULTS
Djokovic – 15/5
Fritz – 24/1

BREAK POINTS WON
Djokovic – 4/9
Fritz – 3/12

Naomi Osaka and Garbine Muguruza set up a blockbuster clash at the Australian Open, while Aryna Sabalenka cannot wait to face Serena Williams.

As Williams was tested before winning through, Osaka and Muguruza raced through their third-round outings in Melbourne on Friday.

Osaka and Muguruza dropped just seven games between them to set up what will be their first meeting, which will take place without fans in attendance as Victoria prepares to move into a five-day lockdown beginning on Saturday due to coronavirus concerns.

Sabalenka also progressed and will next face Williams, while Simona Halep cruised through.

OSAKA, MUGURUZA STORM THROUGH

Osaka, the three-time grand slam champion, brushed past fellow seed Ons Jabeur 6-3 6-2 in the third round.

The Japanese star, winner of the Australian Open in 2019, is looking forward to facing fellow major champion Muguruza.

"I've practised with her once, but it was on grass, and I was younger. It was maybe like a couple years ago," Osaka said.

"But I just remember being really impressed by her, and for me, I've watched her win Wimbledon and win the French Open when I was younger, and I've always wanted to have the chance to play her. So for me, this is really exciting."

A finalist at the Yarra Valley Classic last week, Muguruza's strong start to the Australian Open continued with a 6-1 6-1 thrashing of Zarina Diyas.

"I don't think we've played each other before. Just looking forward for a fourth round, a good fourth round, playing the top players," Muguruza – who has lost just 10 games in the first three rounds – said ahead of facing Osaka. "I feel like that's always the right way, you know, a good sign. Just expecting a good match."

JOB DONE FOR SERENA

Williams' bid for a record-equalling 24th grand slam singles title remains on track after overcoming Russian teenager Anastasia Potapova 7-6 (7-5) 6-2.

In her 101st Australian Open match, Williams secured her 90th career victory in Melbourne. The 39-year-old also improved her overall slam record to 360-51 – Martina Navratilova (306-49) is the only other player to pass 300 wins in the Open Era.

Next up for Williams is Sabalenka, who was too good for Ann Li, winning 6-3 6-1 to reach a major fourth round for just the second time in her career and first in Melbourne.

The Belarusian seventh seed is not daunted by the task facing her when she meets the American for the first time.

"I want to get this thrill. Can I say thrill? I said it right. So it's going to be a thrill. But, yeah. I'm going to do everything I can," Sabalenka said.

HALEP THROUGH AS SEEDS CRUISE

Halep reached the fourth round in Melbourne for the sixth time with a convincing 6-1 6-3 win over Russian 32nd seed Veronika Kudermetova.

Awaiting the two-time major winner in the fourth round is Iga Swiatek after the Polish 15th seed got past Fiona Ferro 6-4 6-3.

Swiatek thrashed Halep 6-1 6-2 on her way to the French Open title last year.

Marketa Vondrousova, the 2019 French Open runner-up, reached the fourth round of the Australian Open for the first time after beating Sorana Cirstea 6-2 6-4.

Up next for the Czech 19th seed is Hsieh Su-wei, who battled past Sara Errani 6-4 2-6 7-5 after two hours and 44 minutes.

Errani had won her previous three meetings with Hsieh in straight sets, including winning a set 6-0 - known as a 'bagel' in tennis parlance - in each of those victories.

It meant Hsieh, 35, had a simple plan against the Italian.

"I don't remember when I lose to someone but someone reminded me I eat the bagel every time so I said, 'Okay, I will try to not take any bagel today'," she said.

Fans were forced to leave Rod Laver Arena with Novak Djokovic's third-round match at the Australian Open still in progress. 

With Victoria entering a five-day lockdown from Saturday due to coronavirus concerns, spectators were told to leave Melbourne Park before 23:30 local time (12:30 GMT). 

Restrictions were coming into place in Victoria from 23:59 local time (12:59 GMT). 

Djokovic's clash against Taylor Fritz was the only match still in progress, although fans were informed to leave amid increasing drama. The world number one led by two sets to one but was struggling with a suspected abdominal injury in the fourth. 

There were boos when the announcement was made, with a message also displayed inside the arena. Play was briefly suspended as fans were moved out. 

No spectators will be allowed at the year's first grand slam for the next five days, although the tournament will continue. 

Dominic Thiem came from behind to edge Nick Kyrgios in a five-set epic in the Australian Open third round on Friday.

Thiem, last year's runner-up in Melbourne, fought back to win 4-6 4-6 6-3 6-4 6-4 on John Cain Arena.

The Austrian third seed was unable to match Kyrgios' energy levels early on, but the reigning US Open champion responded to reach the fourth round of a major for the 15th time in his career.

Thiem, who will face Grigor Dimitrov in the fourth round, was in impressive form after his slow start, finishing with 57 winners and just 28 unforced errors.

Kyrgios was getting the crowd – full of energy ahead of Victoria going into a five-day lockdown from Saturday due to coronavirus concerns – involved from the warm-up, while Thiem appeared flat.

An underarm ace saw Kyrgios take a two-sets-to-love lead as he looked in control before Thiem responded.

Coming from 15-40 down in the opening game of the third set, Thiem won 20 consecutive points on serve.

Kyrgios steadied and held after a marathon game to begin the fourth set, but he could not deny Thiem – who continued to hold serve comfortably – in the ninth as the Austrian broke with a cross-court forehand pass.

A point penalty for ball abuse appeared to bring Kyrgios to life, but Thiem saved a break point and served out the set.

The crucial and only break of the fifth set came for Thiem in the seventh game after several fine returns and he closed out his victory with a spectacular backhand winner down the line.

Naomi Osaka admitted it was "a bit funny" to be deemed an essential worker as the Australian Open goes on.

The year's first grand slam is set to continue without fans from Saturday as Victoria heads into a five-day lockdown amid coronavirus concerns.

Professional athletes have been deemed "essential workers", meaning the Australian Open can continue.

Osaka, who raced into the fourth round with a 6-3 6-2 victory over Ons Jabeur on Friday, said that seemed strange.

Asked how she felt about being described as an essential worker, the Japanese star told a news conference: "Well, I'm not really sure.

"That kind of seems a bit funny. But I don't know, I don't make the rules. I'm just here just trying to have fun."

Three-time grand slam champion Osaka will face Garbine Muguruza in a blockbuster fourth-round clash.