World number one Novak Djokovic had enough on his plate already on Wednesday without marauding Russian Daniil Medvedev pummelling him to a shock 6-3, 6-3 defeat at the ATP Finals.
Novak Djokovic ruthlessly took Matteo Berrettini apart at the ATP Finals on Sunday as he began his quest to reclaim the number one ranking by winning his opening group match 6-2, 6-1.
Rohan Bopanna and his Australian partner Matthew Ebden advanced to the quarterfinals
Learner Tien is the youngest American man to reach the third round of the Australian Open since an 18-year-old Pete Sampras in 1990.
Earlier this week, Bopanna and Ebden had clinched a spot in the prestigious season-ending ATP Finals.
Muguruza wins all-Spanish clash with Badosa at WTA Finals
Stefanos Tsitsipas confirmed his meteoric rise into the highest echelon of men's tennis by battling back to beat Austrian Dominic Thiem 6-7(6) 6-2 7-6(4) in a compelling title duel at the ATP Finals on Sunday.
World number one Novak Djokovic began his quest for a sixth title at the season-ending ATP Finals with a 7-6(4), 6-2 victory over Norway's Casper Ruud in their round robin encounter in Turin on Monday.
Sinner gives the impression of a player with all the answers against whoever he comes up against, but the off-court questions he is likely to face about the doping case that surfaced in August might be harder to shrug off.
Jannik Sinner overpowered American Taylor Fritz in the final to become the first Italian man to win the US Open singles title.
Sinner remains the man to beat at Melbourne Park even as doping officials seek a two-year ban for the world number one for failing two drugs tests last March.
Australia now have the opportunity to avenge last year's final defeat by Italy after world number one Jannik Sinner inspired the holders to a 2-1 victory over Argentina.
However, the 33-year-old Spaniard will not know until later on Friday whether his Herculean effort was in vain.
Not that cash will be the motivator for world number one Novak Djokovic, Rafa Nadal, Dominic Thiem, Tsitsipas, Daniil Medvedev, Alexander Zverev and debutants Andrey Rublev and Diego Schwartzman when the tournament's 50th edition starts on Sunday.
Novak Djokovic is ready to challenge Jannik Sinner and Carlos Alcaraz at the Grand Slam stage when he returns to action at the Australian Open after an underwhelming campaign this year, the 24-times champion said.
Alexander Zverev cruised past Frenchman Lucas Pouille in straight sets in the first round of the Australian Open on Sunday.
Defending champions Italy moved into the Davis Cup final after a 2-0 win over Australia on Saturday as Jannik Sinner defeated Alex de Minaur in straight sets to follow up Matteo Berrettini's victory over Thanasi Kokkinakis.
Roger Federer got back on track at the ATP Finals with a 7-6(2), 6-3 defeat of Italian Matteo Berrettini on Tuesday.
Medvedev became only the fourth player in ATP history to beat the world's top three at the same tournament.
Ronaldo got involved in ball kid duties while watching world number one Novak Djokovic's opening match against John Isner of America as the tennis ball bounced into the stands near the first row where he was sitting.
Jannik Sinner spearheaded Italy's charge towards a second successive Davis Cup title with a 2-0 victory over the Netherlands in the final at the southern Spanish city of Malaga on Sunday.
The 32-year-old debutant at the ATP's blue riband event won the first 11 games of the round-robin clash before a relieved Nishikori finally got on the scoreboard with an angled winner.
Australia booked their place in the Davis Cup semi-finals as doubles pair Matthew Ebden and Jordan Thompson clinched the deciding rubber against the United States on Thursday.
Only once in 16 previous appearances has Federer not survived the group stage, back in 2008. IMAGES from the ATP Finals played at The O2 Arena in London on Sunday
The two cases shocked the tennis world with many fuming at how they were handled by the authorities.
Teenager Kei Nishikori became the first Japanese to reach an ATP final at the Delray Beach International.
Tsitsipas had lost all five previous matches against the Russian, but turned the tables in impressive fashion.
The 36-year-old was given a thorough workout by Sock although had he been a little more clinical the scoreline would have been more heavily-weighted in his favour.
Having dug in early on to stay with Federer, Nishikori ended up running away with the match to inflict a first straight sets defeat in the ATP Finals round-robin stages on the 20-time Grand Slam champion.
The 20-year-old German, ranked three in the world, was hot and cold against Croatia's Marin Cilic but, when it mattered most, he produced his best tennis to win 6-4, 3-6, 6-4.
Alexander Zverev became the first German to reach the last four at the ATP Finals for 15 years as he beat American John Isner 7-6(5), 6-3 at the O2 Arena on Friday.
Grigor Dimitrov claimed the biggest title of his career and sent out a huge statement of intent as the stylish Bulgarian beat David Goffin 7-5, 4-6, 6-3 to win the ATP Finals.
Roger Federer has secured his place in the ATP Finals for a record 15th time after the Swiss world number three won a record eighth Wimbledon title on Sunday, the Association of Tennis Professionals confirmed on Monday.
Roger Federer rediscovered his verve in the nick of time to outclass Austrian Dominic Thiem 6-2, 6-3, on Tuesday, and maintain his hopes of reaching the last four at the ATP Finals.
The victory saw him move up by three places to stand only behind Spain's Rafael Nadal and Swiss star Roger Federer.
Djokovic etched his name in history by clinching a record 24 Grand Slam titles
Jannik Sinner won his maiden Grand Slam title at the Australian Open on Sunday.
It was the 31-year-old Serb's second comfortable win in the Gustavo Kuerten group and combined with Marin Cilic's 6-7(2), 6-3, 6-4 defeat of American John Isner later in the day, he sealed his place in the semi-finals at the year-ender for the eighth time.
Images from the men's singles action at the US Open on Sunday.
A few days after it appeared as though a Roger Federer impersonator had gatecrashed the 02 Arena, the Swiss great resumed normal service to outplay Kevin Anderson and reach the last four of the ATP Finals on Thursday.