Jannik Sinner cited remaining mentally consistent as being key to opening his ATP Finals campaign with a victory over an injured Felix Auger-Aliassime on Monday.
Sinner kickstarted his title defence with a 7-5 6-1 win over Auger-Aliassime, who injured his left leg and required a medical timeout following the first set.
The Canadian called for the physiotherapist twice in the second set, with the issue clearly affecting his performance as Sinner strolled to victory in front of a raucous home crowd.
Sinner's win means he has now won his last 27 matches on indoor courts, while he has not dropped a set at the ATP Finals since his 2023 final defeat to Novak Djokovic.
Indeed, the highest of any currently active player, Sinner (84.6%, 11-2), now only trails
Ilie Nastase (88.0%, 22-3) for win rate at the ATP Finals, since the event's inauguration in 1970 - minimum 10 matches.
"You still have to be very consistent, with a great balance on the court," said Sinner, when asked about facing a physically struggling opponent.
"Especially mentally, it is a bit different, but at the same time, it is an advantage. You have to say that. You have to use it in the right way, even if you don't want it to be like this. "
84.6 - The highest of any currently active player, Jannik Sinner (84.6%, 11-2) only trails Ilie Nastase (88.0%, 22-3) for win rate at the ATP Finals, since the event’s inauguration in 1970 – minimum 10 matches.#NittoATPFinals | @atptour @ATPMediaInfo pic.twitter.com/Vr94ZPKA2G
— OptaAce (@OptaAce) November 10, 2025
Sinner is now top of Bjorn Borg Group after his triumph, joining Alexander Zverev, who he faces next at the year-end tournament, at the summit of the standings.
But the second seed was certainly put through his paces in the opening set, with Auger-Aliassime saving two break points in the sixth game as well as a set point.
"It was a very tough match until 6-5," Sinner added. "I had some chances to break. He served very well, only once I missed a return, but it can happen.
"He played very aggressive tennis, so I'm happy to overcome a very tough test today.
"Obviously, winning the first match is very important in this competition and this format.
"I hope it's nothing too serious. I wish him a very speedy recovery and, hopefully, he is back to 100 per cent physically. "
Along with trying to retain his ATP Finals crown, Sinner is also looking to take the year-end number one ranking away from rival Carlos Alcaraz.
The 24-year-old must defend his title and hope Alcaraz loses a group match and does not reach the final to move back to the top of the rankings.
Alcaraz is in the Jimmy Connors Group, and started his campaign with a straight-set win over Alex de Minaur on Sunday.
