Matteo Berrettini survived a scare to eventually progress to the fourth round at the Indian Wells Masters on Tuesday.

The Italian sixth seed had to fight from 2-5 down in the second set and saved three set points, before powering through to triumph 6-4 7-5 over Lloyd Harris.

"I got a little bit nervous," Berrettini said post-match. “I didn’t like how I handled the start of the second set. I let the anger get out a little bit, which helped. I found the right balance in order to break him in the important moment and then I had the momentum.”

The world number six found another level in reeling off five straight games, and will now face unseeded Miomir Kecmanovic, who accounted for Botic van de Zandschulp 7-6(6-3) 7-5.

Taylor Fritz was also pushed by Spanish qualifier Jaume Munar, taking a third-set tiebreaker to progress to the fourth round.

The 20th-seeded was made to work for it in a match that lasted just under three hours, but Munar feel short in the clutch, with two unforced forehand errors in the closing tiebreak to give Fritz a three-point gap.

In Tuesday's last game, Andrey Rublev showed rare composure to progress past Frances Tiafoe 6-3 6-4. 

Neither got off to the best of starts, with Rublev and Tiafoe sharing service breaks in the opening four games of the first set. The characteristically volatile Rublev managed to regroup, though, and stayed calm even when Tiafoe got his home crowd on side. 

Despite a low 67 percent on first serve, Rublev won 83 percent of those points, while Tiafoe did himself no favours with an even lower 58 percent first-serve rate.

Last-year’s semi-finalist will face 29th-seeded Alex de Minaur, who defeated Tommy Paul 7-6(6-2) 6-4.

The Australian world no. 31 faced immediate difficulty on service, with only his second service game going to eight consecutive deuces, after five saved break points. He eventually saw the match through, after breaking for 4-3 in the second set.

Fellow seeds Hubert Hurkacz and Grigor Dimitrov both went through relatively unscathed, with respective wins over Steve Johnson and Alexander Bublik.

Dimitrov will face John Isner, who saw past Diego Schwartzman 7-5 6-3 in Tuesday’s other result.

Alexander Zverev saved two match points and battled back to salvage a dramatic victory over Jenson Brooksby at the Mexican Open in what was the latest finish in tennis history.

Second seed Zverev – the defending champion in Acapulco - wrapped up a dramatic win at 04:55 local time after his own lengthy contest had followed two other epic three-setters earlier on the schedule.

Zverev at one stage looked like he was on the way out but ultimately triumphed 3-6 7-6 (12-10) 6-2 to book a second-round tie against Peter Gojowczyk.

The German had beaten Brooksby in a match that also went to a decider when they clashed at Indian Wells in October and he was pushed to the limit again in a battle lasting 200 minutes.

Having dropped the first set, Zverev had to fend off three break points at 3-3 in the second and saved match points at 6-5 and 10-9 down as part of an epic tie-break that went in his favour. 

Zverev was then more comfortable as he broke twice in the decider to seal victory, his American opponent paying the price for converting just one of his seven break-point opportunities in a match that made history for its late finish.

The previous latest ATP finish time was Lleyton Hewitt's 2008 Australian Open clash with Marcos Baghdatis, which ended at 04:34 local time.

Elsewhere, Stefan Kozlov overcame cramps in the second set to outlast Bulgarian Grigor Dimitrov 7-6 (10-8) 5-7 6-3, with that match lasting three hours and 21 minutes.

John Isner sent down 29 aces and saved a match point as he trailed 5-2 in the third set, ultimately winning 7-5 6-7 (4-7) 7-6 (7-3) over veteran Fernando Verdasco in another epic topping the three-hour mark that helped to push back the start time for Zverev and Brooksby.

Seventh seed Taylor Fritz got past Frenchman Adrian Mannarino 6-3 6-3, while Dusan Lajovic knocked off Sebastian Korda 6-4 4-6 7-5 and eighth seed Pablo Carreno Busta beat Oscar Otte in straight sets.

At the Chile Open in Santiago, eighth seed Facundo Bagnis won 6-3 6-0 over Bernabe Zapata Miralles in the round of 32.

Brazilian Thiago Monteiro got past local Nicolas Jarry 7-6 (11-9) 6-4, while qualifier Juan Ignacio Londero and wildcard Thiago Seyboth Wild also progressed.

Alexander Zverev saved a match point and battled back to salvage a dramatic victory over Jenson Brooksby at the Mexican Open in what was the latest finish in tennis history.

Second seed Zverev – the defending champion in Acapulco - wrapped up a dramatic win at 04:55 local time after his own lengthy contest had followed two other epic three-setters earlier on the schedule.

Zverev at one stage looked like he was on the way out but ultimately triumphed 3-6 7-6 (12-10) 6-2 to book a second-round tie against Peter Gojowczyk.

The German had beaten Brooksby in a match that also went to a decider when they clashed at Indian Wells in October and he was pushed to the limit again in a battle lasting 200 minutes.

Having dropped the first set, Zverev had to fend off three break points at 3-3 in the second and saved a match point at 6-5 as part of an epic tie-break that went in his favour. 

Zverev was then more comfortable as he broke twice in the decider to seal victory, his American opponent paying the price for converting just one of his seven break-point opportunities in a match that made history for its late finish.

Elsewhere, Stefan Kozlov overcame cramps in the second set to outlast Bulgarian Grigor Dimitrov 7-6 (10-8) 5-7 6-3, with that match lasting three hours and 21 minutes.

John Isner sent down 29 aces and saved a match point as he trailed 5-2 in the third set, ultimately winning 7-5 6-7 (4-7) 7-6 (7-3) over veteran Fernando Verdasco in another epic topping the three-hour mark that helped to push back the start time for Zverev and Brooksby.

Seventh seed Taylor Fritz got past Frenchman Adrian Mannarino 6-3 6-3, while Dusan Lajovic knocked off Sebastian Korda 6-4 4-6 7-5 and eighth seed Pablo Carreno Busta beat Oscar Otte in straight sets.

At the Chile Open in Santiago, eighth seed Facundo Bagnis won 6-3 6-0 over Bernabe Zapata Miralles in the round of 32.

Brazilian Thiago Monteiro got past local Nicolas Jarry 7-6 (11-9) 6-4, while qualifier Juan Ignacio Londero and wildcard Thiago Seyboth Wild also progressed.

The top two seeds Casper Ruud and Diego Schwartzman will face off in the Argentina Open final after the latter won two matches on Saturday to progress at his home event.

The Argentine world number 14 had to overcome countryman Francisco Cerundolo 6-3 2-6 5-7 earlier on Saturday after their quarter-final had been interrupted by rain on Friday evening.

The match was tied at 1-1 in the third set when rain intervened, with Schwartzman triumphing when play resumed to earn a semi-final date with third seed Lorenzo Sonego.

Schwartzman would later beat Sonego 7-5 3-6 6-2 in almost three hours on a busy day for the 2020 French Open semi-finalist.

World number eight Ruud progressed with a routine 6-3 6-3 victory over Argentine sixth seed Federico Delbonis.

At the Dallas Open semi-finals, Reilly Opelka and John Isner broke the record for the longest tiebreaker on the ATP Tour since 1990.

Second seed Opelka triumphed over fellow American Isner but it was not easy, winning 7-6 (9-7) 7-6 (24-22).

Opelka sent down 39-21 aces across the match, earning a spot in the final against fourth seed Jenson Brooksby who beat Marcos Giron 6-4 6-7 (4-7) 7-6 (7-5).

Casper Ruud began his Argentina Open title tilt with an impressively routine defeat of Roberto Carballes Baena.

The Norwegian, who is the top seed, saw off his opponent 7-6 (7-2) 6-3 to set up a quarter-final clash with home hopeful Federico Coria, who defeated Dusan Lajovic 4-6 7-5 6-4.

Ruud was taking to the court for the first time since being in ATP Cup action in early January, with ankle injury ruling him out of the Australian Open.

But on the scene of his maiden ATP title win in 2020, Ruud – who has won five tournaments since – looked in good shape.

"I feel, obviously, very good in Buenos Aires. I was a bit nervous coming back because it's the first time I have to defend a title," he said.

"Everything is a bit different since two years ago. When I won here it was a surprise. I was young.

"[This] was a good start. First time playing on clay in six months, so everything is a bit new again.

"Of course, I prefer to play on clay, but it takes some time to get used to the court and playing points."

Third seed Lorenzo Sonego also advanced through to the last eight in straight sets, the Italian beating Sebastian Baez 6-3 6-3 to set up a meeting with Fernando Verdasco.

Unseeded Spaniard Verdasco, seeking an eighth career title, progressed thanks to a hard-fought 2-6 6-3 7-5 win over Thiago Monteiro.

At the Dallas Open, John Isner won his opening match on home soil with a 7-6 (7-1) 6-7 (7-9) 7-6 (7-5) victory over Kevin Anderson.

Isner will next take on either Vasek Pospisil or Jurij Rodionov, with the qualifiers scheduled to meet on Thursday.

Marcos Giron and Jordan Thompson are also in the quarter-finals after seeing off Liam Broady and Brandan Nakashima respectively.

Novak Djokovic has been warned by Boris Becker that his "stubbornness" could prevent him being remembered as the greatest tennis player that ever lived.

World number one Djokovic, who has not declared his COVID-19 vaccination status, seemed set to play in this month's Australian Open after he was granted a medical exemption by tournament organisers.

That was required for any player who has not been fully vaccinated. One theory that has been widely suggested is that Djokovic may have been entitled to an exemption after a positive test for COVID-19 in the past six months, although he has not confirmed he has recently had the virus.

However, Djokovic is now set to spend the weekend in a Melbourne detention hotel in which refugees and asylum seekers are also being kept, after Australian Border Force's decision to cancel his visa application.

A court hearing on Monday should provide a resolution to the saga, with Djokovic's legal team set to battle for his right to enter the country and play in the season's first grand slam, at which he would be bidding to win a record 21st men's singles major title. The Australian Open gets under way on January 17.

Becker coached Djokovic for three seasons, from 2014 to 2016, and told the Daily Mail the 34-year-old Serbian is "making a big mistake in not getting vaccinated".

The German said the decision "is one that threatens what remains of his career and his chance to cement himself as the greatest player of all time".

Becker, a six-time grand slam winner, said: "The same incredible determination which I saw win so many close matches can be a vulnerability with his stubbornness.

"It is not just about Australia. The fact is that we are living in a different world and he is going to find it very hard to live the life of a professional tennis player travelling around without the vaccination.

"Maybe one day we will get back to a more normal situation, but at 34 he does not have much time left to pursue his goals."

There have been protests on the streets of Melbourne and Belgrade, with arrests made by police in the Victorian capital, while Djokovic found some support from within the tennis fraternity on Friday, as American John Isner backed his case.

Isner wrote on Twitter: "What Novak is going through right now is not right. There’s no justification for the treatment he’s receiving. He followed the rules, was allowed to enter Australia, and now he’s being detained against his own will. This is such a shame. #IStandWithNovak".

Nick Kyrgios, who has had his run-ins with Djokovic in the past, labelled Australia's handling of the situation "really bad", while former world number one Andy Roddick also appears to be in Djokovic's corner.

Yet Australia's home affairs minister Karen Andrews rejected any idea that Djokovic was being "held captive".

Andrews told the ABC: "Can I say, firstly, that Mr Djokovic is not being held captive in Australia. He is free to leave at any time that he chooses to do so and Border Force will actually facilitate that.

"Yes, there was a visa issued – that is actually not the issue. It is the second part of that process, which is the specific entry requirements to be able to cross Australia's border and to enter Australia lawfully."

She said Djokovic was not the only tennis case that was under investigation by Australian authorities. A player and an official are reported to be under scrutiny.

"I'm aware of investigations in relation to two individuals by the Australian Border Force," Andrews said. "They're going through their processes of investigation.

"And at some time, they will brief me, but all I can absolutely assure you and the rest of Australia of is that the Australian Border Force will take absolutely the appropriate action."

Team Europe are poised to seal yet more Laver Cup glory after producing another dominant display against Team World, though the focus was on Nick Kyrgios following comments about his long-term future.

Europe swept Saturday's four matches in Boston to stand on the cusp of a fourth consecutive Laver Cup triumph – the defending champions lead 11-1 and require just two more points to clinch the title.

Stefanos Tsitsipas blitzed Team World's Kyrgios 6-3 6-4 at TD Garden, where Olympic Games gold medallist Alexander Zverev beat John Isner 7-6 (7-5) 6-7 (6-8) 10-5 before US Open champion Daniil Medvedev made light work of Denis Shapovalov 6-4 6-0.

Team Europe secured their fourth win of the day in the doubles – Tsitsipas and Andrey Rublev teaming up to defeat Isner and Kyrgios 6-7 (8-10) 6-3 10-4.

After Kyrgios' straight-sets loss to Greece's Tsitsipas, the 26-year-old Australian star casted doubt over his tennis future.

"This is my probably my last Laver Cup," former world number 13 Kyrgios – an Australian Open and Wimbledon quarter-finalist – told reporters post-match. "I don't know how much longer I will be in tennis.

"This is my last event of the year. I will get my body right ahead of the Australian Open.

"My mum is not doing too well with her health. I'd like to go back and see her."

"As long as I'm on the court, I will try and give my best, but I'm not going to lie and say that I'm going to plan to play four or five more years on tour," Kyrgios said. "That's just not me."

Playing for the first time since earning his maiden grand slam trophy at the expense of record-chasing Novak Djokovic at Flushing Meadows, world number two Medvedev suffered no letdown against Shapovalov.

"I played unbelievably, especially [in] the second set," Russia's Medvedev said in his on-court interview. "I didn't know what to expect because after the US Open, I didn't play for a week and a half. Came here, practised as much as I could the past three days, so I didn't hit [that] many balls, but was surprisingly feeling well.

"I wanted to show that also today. [The] first [set] was not easy, the ball was not going as fast as I wanted [and] he was playing really good. And then I just couldn't miss a ball anymore. I'm really happy about [that]."

Nick Kyrgios, John Isner and Reilly Opelka have been named by Team World captain John McEnroe as his final three picks for the Laver Cup.

The trio join Denis Shapovalov, Felix Auger-Aliassime and Diego Schwartzman for the team event which runs from September 24-26 at TD Garden in Boston.

Laver Cup newcomer Opelka rose to a career-high world number 23 ranking en route to his first ATP Masters 1000 final in Toronto and defeated world number three Stefanos Tsitsipas, who will play for Bjorn Borg's Team Europe.

Isner, who has featured for Team World since the inaugural event in 2017, reached the semi-finals in Toronto and claimed his 16th ATP Tour title in Atlanta at the start of August.

He described the Laver Cup as "a highlight of my year", adding: "To be on a team with guys we're normally competing against is so different and so much fun. We come together so well as a group, the chemistry is awesome and it's such a great environment to be part of."

Australian firebrand Kyrgios is a striking inclusion in Team World's roster, while Team Europe will be without their big three: Roger Federer, Rafael Nadal and Novak Djokovic.

Federer and Dominic Thiem were expected to take part in this year's event, though both were forced to withdraw with injuries.

However, Borg's men still boast six of the world's top 11. World number two Daniil Medvedev leads the line-up, with Tsitsipas and Tokyo Olympics gold medallist Alexander Zverev for company.

Casper Ruud, who collected a 14th win in his last 15 completed matches on tour when he beat Opelka on Wednesday, will feature, while Andrey Rublev and Wimbledon finalist Matteo Berrettini complete the six-man team.

Team Europe have landed the title in each of the three editions of the tournament so far, with Prague, Chicago and Geneva having served as hosts.

Top seed Daniil Medvedev will face Reilly Opelka in the National Bank Open final after the American stunned Stefanos Tsitsipas in a three-set classic in Saturday's semi-finals.

World number 32 Opelka fought back from a set down in Toronto to knock out favoured third seed Tsitsipas in two hours and 32 minutes.

The 23-year-old American triumphed 6-7 (2-7) 7-6 (7-4) 6-4, booking a spot in his first ATP Masters 1000 final.

Opelka sent down 17 aces but also hit 27 groundstroke winners in the shock victory over 2021 Australian Open semi-finalist Tsitsipas who had beaten in-form Casper Ruud in the quarters.

"I played great," Opelka said in his on-court interview. “These courts suit my game, it is no coincidence that John Isner is in the other semi-final.

"Stefanos has definitely improved his returning. Come 5-5 in the first set, a lot of balls started to come back. He is a thinker and has a high tennis IQ, so it was expected, but that is what separates him from the rest of the pack."

Opelka was aided by an excellent first serve percentage of 72 per cent, winning 62 of 81 points when he made his first serve.

Both first two sets went to tiebreaks, with Tsitsipas failing to generate a break point until the third set. Opelka made the first break of the match in the seventh game of the third set and held serve twice after to seal victory.

World number two Medvedev cruised into the decider with a commanding win over John Isner in less than an hour.

Medvedev, who was runner-up in Toronto in 2019, won 6-2 6-2 over the big-serving American, with the match totaling 54 minutes.

Isner could only manage four trademark aces for the match, while the Russian had 11 and broke the American four times from seven opportunities.

Daniil Medvedev and Stefanos Tsitsipas survived three-set scares at the National Bank Open on Tuesday, but five-time tournament champion Rafael Nadal departed Toronto without even taking the court. 

Top seed Medvedev, who won just three games against Nadal in the final in 2019, the last time the tournament was played, prevailed 4-6 6-3 6-4 in his opener against Alexander Bublik.

The man Nadal beat to win the title the previous year, Tsitsipas, failed to convert on five match points in an epic second-set tiebreak but recovered to down Ugo Humbert 6-3 6-7 (13-15) 6-1.

Nadal pulled out ahead of a scheduled match against Lloyd Harris, who beat him last week in Washington as the 20-time grand slam winner struggled with a foot injury. 

Countryman Feliciano Lopez replaces Nadal in the draw and will face Harris on Wednesday. 

Elsewhere Tuesday, sixth seed Casper Ruud needed more than two hours to put away Marin Cilic 6-3 3-6 6-3, while 14th seed Grigor Dimitrov suffered a quick 6-3 6-4 exit against big-serving American Reilly Opelka.

A pair of unseeded veterans advanced, with 2016 finalist Kei Nishikori a 6-4 6-7 (5-7) 6-2 winner over Miomir Kecmanovic and John Isner defeating Alejandro Davidovich Fokini 6-4 6-1 in just over an hour.

Two days after appearing in his first ATP Tour final at the Citi Open, Mackenzie McDonald fell 6-3 6-4 to Benoit Paire in his Toronto opener. 

In other first-round matches, Karen Khachanov beat Cameron Norrie 6-4 5-7 6-4, Frances Tiafoe downed Yoshihito Nishioka 6-4 6-3, Dusan Lajovic handled Emil Ruusuvuori 3-6 6-3 6-3 and Nikoloz Basilashvili defeated Jenson Brooksby 2-6 6-0 6-4.

John Isner has claimed his sixth Atlanta Open title after a straight sets win over American teenager Brandon Nakashima in Sunday's final.

Isner, who had won five of the past seven Atlanta Opens held, triumphed 7-6 (10-8) 7-5 in one hour and 56 minutes.

The victory is world number 35 Isner's 16th ATP Tour career title. It is also 36-year-old Isner's first title since 2018.

Isner sent down 21 aces on route to the win, where his serve was not broken once with Nakashima unable to convert any of his three break points.

The 208cm American broke for the first time in the crucial game, deciding the contest with Nakashima dishing up a double fault on match point.

Nakashima had beaten Isner in last week's Los Cabos Open semi-finals but the veteran has made the Atlanta court his own.

The 19-year-old had one set point in the first set tiebreaker which he failed to convert before Isner capitalized with his third, winning 10-8.

Isner's dominance was on his serve, winning 81 per cent of first serve points, which he landed 58 of 77, with break points rare until the final three games.

The big American had three break points at 5-4 in the second set but Nakashima saved them all, before the teenager let slip two break points in the next game.

Isner converted a single break point in the 12th game of the second set to salute.

One-third of John Isner's 15 career ATP titles have come at the Atlanta Open and the American will play for another Sunday against an up-and-coming countryman. 

Isner defeated Tayor Fritz 7-6 (7-4) 5-7 6-3 on Saturday to reach his first ATP Tour final this year after losing in the semis three times. 

One of those semi-final setbacks came last week in Los Cabos to Brandon Nakashima, who will be Isner's opponent Sunday. 

The 19-year-old Californian, ranked a career-best 115th, rallied to beat Finland's Emil Ruusuvuori 3-6 6-4 6-3 in the other semi. 

Nakashima defeated top seed Milos Raonic earlier this week and is riding high as he looks for his first ATP title. 

He is the first US teenager to reach the final in consecutive weeks since 18-year-old Andy Roddick won his first two ATP tournaments at Atlanta and Houston in the spring of 2001. 

Roddick's maiden title came in an earlier version of the Atlanta event. Since it was revived in 2010, Isner has won five of the 10 titles, with the first coming in 2013 about a week before Nakashima's 12th birthday.

"I didn’t know much about [Nakashima] prior to last week," Isner told the ATP's website. "But he kicked my ass last week, so we’ll see what I can do tomorrow.

"He’s 19 years old, that’s crazy. I was fishing on a boat when I was 19, here he is in the final of an ATP event.”

Fifth seed Taylor Fritz defeated compatriot fourth seed Reilly Opelka in a three-set epic in the quarter-finals at the Atlanta Open on Friday.

Fritz, who reached last week's Los Cabos Open semi-finals and is currently ranked 36th in the world, edged out Opelka 7-6 (7-5) 6-7 (3-7) 7-6 (7-4) in just under three hours.

The pair sent down a combined 48 aces, with Fritz claiming 25 of them, with all sets going to tiebreakers, with no breaks of serve.

Third seed Cameron Norrie was bundled out by Finnish world number 78 Emil Ruusuvuori in straight sets.

Norrie, who won last week's Los Cabos Open for his maiden ATP Tour title, was beaten 7-6 (7-1) 6-3 by the Finn.

Ruusuvuori will take on teenager Brandon Nakashima in the semi-finals, after the American – who was runner-up to Norrie in Los Cabos - beat Jordan Thompson 7-6 (7-5) 7-5.

Sixth seed John Isner sent down 30 aces as he got past Australian qualifier Chris O'Connell 7-6 (7-5) 6-7 (3-7) 6-4.

Cameron Norrie breezed past Nick Kyrgios and John Isner downed countryman Jack Sock to advance to the quarter-finals at the Atlanta Open on Thursday. 

The third-seeded Norrie defeated Kyrgios 6-1 6-4 in less than an hour as he tries for a second consecutive title after collecting his first ATP Tour championship at Los Cabos last week. 

The former University of Georgia star Isner, a five-time champion in Atlanta, beat Sock 7-6 (8-6) 6-4 despite serving only 13 aces after hitting 36 in his previous match. 

Second-seeded Jannik Sinner fell 7-6 (9-7) 6-4 to Australian qualifier Christopher O'Connell, leaving the tournament without its top two seeds after Milos Raonic was upset by Brandon Nakashima on Wednesday. 

O'Connell, ranked 132 in the world to Sinner's 23, had not won a main-draw match this year before defeating Denis Kudla in the opening round and will now face Isner in the quarters.

Norrie will meet Emil Ruusuvuori, who advanced when Benoit Paire retired down 3-0 in the third set after the pair had split the first two sets 4-6 6-4. 

Ruusuvuori is into his second career ATP quarter-final after making it to the semis at Nur-Sultan last year. 

Sixth seed John Isner sent down an Atlanta Open joint record 36 aces as he overcame countryman Jeffrey John Wolf in three sets on Tuesday.

World number 35 Isner was dominant on his first serve, winning 6-4 6-7 (3-7) 6-4 to claim a spot in the second round where he will face Jack Sock who beat Ricardas Berankis in three.

Isner's 36 aces equaled the previous Atlanta Open record set by Sam Querrey on Monday in his three-set win over Peter Gojowczyk.

American fifth seed Taylor Fritz also progressed on Tuesday with a 6-3 6-4 victory over Russian Evgeny Donskoy.

French seventh seed Benoit Paire got past Japan's Yasutaka Uchiyama 7-5 6-7 (2-7) 6-4, while enigmatic Australian Nick Kyrgios beat South African Kevin Anderson 7-6 (7-4) 6-3.

Teenage American talent Brandon Nakashima knocked out Trent Bryde, while Australian Chris O'Connell beat Denis Kudla and Finland's Emil Ruusuvuori got past Mackenzie McDonald 7-6 (7-3) 7-5.

Nakashima, who got a special exemption entry into the Atlanta Open, next takes on top seed Milos Raonic.