TURIN, Italy — Alexander Zverev was beaten for the fourth time this year by Italy's Jannik Sinner in a 6-4, 6-3 defeat at the ATP Finals on Wednesday, but the German does not believe the scoreline reflected his performance.

Zverev's previous loss to Sinner came 11 days ago, going down 6-0,6-1 at the Paris Masters, but in Turin the two-time winner of the season-ending championships had the majority of break points, but unlike the Italian, he failed to take advantage of them.

Sinner forced break points in one game in each set, enough to claim victory and a place in the semifinals, while Zverev had seven across four games.

In the Vienna Open final 17 days ago, Zverev managed to win one set, but this time around the German could not find a way past Sinner's serve.

"I think generally today, the biggest difference was how he was serving on the break points," Zverev said.

"I had more break points than him. I felt very good from the baseline, actually better than in Vienna almost, when we were in the rally.

"To be honest, he had two chances to break me, and he used both of them. I had a lot of chances, and I didn't use any."

Sinner hit 12 aces, many of which came at crucial points. In the opening game alone, the Italian served up four aces, two of which saved break points, and he came from 0-40 down early in the second set with an ace winning that game.

"Sometimes, when he's serving like this, it's even more difficult because, seven break points, seven first serves, not one second serve I had," Zverev said.

"I was not even in the rally at all. I think I made one return. He hit a forehand winner.

"He improved his serve a lot. All in all, from the baseline, how the game was, I thought it was a good match, which was perhaps closer than the score suggests."

Zverev was asked if Sinner's performance was unplayable.

"It's not unplayable. I had many opportunities. He had one, he used the chance," Zverev replied.

"Of course, I think it's quite easy for you guys to ask these questions, because the score says 6-4, 6-3.

"If you look deeper into the match, I really believe that it could have been better than 6-4, 6-3.

"So... don't always judge it by the score."

Zverev won his opening match against Ben Shelton, and a win over Felix Auger-Aliassime on Friday would see him advance to the semifinals from the Bjorn Borg Group. From there, he could meet defending champion Sinner again in the decider.

"Listen, I hope to see him again this week, it's as simple as that," Zverev said.

World No 1 Sinner is bidding to retain his title at the prestigious end-of-season tournament.

The 24-year-old was not at his best and struggled with a hand problem at the start of the match, but still had more than enough to see off Zverev for the fifth straight time. Zverev hasn't beaten Sinner since the 2023 US Open.

Sinner was brutal on his serve, rattling in 12 aces, and once he took the first set with his third break point of game 10 he never looked back.

"If we watch the match today, there were one or two points, that's why I won the first set," Sinner told reporters.

"Couple of points, that's why I won the second set. If those points go the other way, maybe it's the same score the opposite way. You never know."

Zverev needed to win in straight sets to book his place in the semis but will now have to beat Auger-Aliassime, a 4-6, 7-6 (7), 7-5 winner over Shelton, in his final group match on Friday in order to progress.

But, he cut an irritated figure on court, frustrated by his inability to capitalize on any of his seven break points, a series of unforced forehand errors and at one point by a flashing advertising sign.

Amazing Auger-Aliassime

Canada's Auger-Aliassime won just his second ever match at the season-ending tournament with a battling display, coming back from a poor start to boost his hopes of reaching the semifinals.

"Obviously, we know how well he can serve, but I felt that if I was able to engage in the rallies, neutralize his serve, maybe I would get a chance at some point," Auger-Aliassime told Sky Sport.

"I think I played great, very aggressive, hitting very good balls off my backhand and forehand, so I went for it and in the end it paid off."

Auger-Aliassime's imposing service game, which included nine aces, eventually broke down Shelton, whose erratic play cost him a debut win at the Finals.

The 25-year-old showed no signs of being hampered by the calf problem which affected his opening loss to Sinner, and he will face Zverev on Friday with a chance of making the knockout stage.

"I think there's a bit of a learning curve everywhere you go. Different tournament, different atmosphere, different format that I've never played in before, and obviously playing the best players in the world," Shelton told reporters.

Shelton looked to be in control when he won the first set at the first opportunity, breaking Auger-Aliassime's serve for the second time just after having his initial break canceled out.

Auger-Aliassime won a tight second set that went with serve until the tie-break, when Shelton had to save three set points, before eventually conceding the match lead with a double-fault.

He won the match at the third time of asking at the end of another bruising set, breaking Shelton and getting a win on the board.

Agencies