Jannik Sinner has admitted he needs to "improve" his fitness if he is to lift a second Grand Slam trophy next month. The 23-year-old will be looking to claim the second major title of his career at the US Open after winning the Australian Open in January.

Sinner faced a gruelling duel with German ace Alexander Zverev in the Cincinnati Masters semi-finals on Sunday in a match that lasted three hours and seven minutes.

But the Italian battled through a hip issue to book his place in the showpiece match after overcoming his rival 7-6, 5-7, 7-6.

"It means a lot to me. It’s a very different moment, what I’m going through, so I’m very happy about this result," Sinner explained in his on-court interview after the match.

"The physical aspect of course I have to improve because if I want to win Grand Slams or a bigger title I have to be for sure more in shape. I just try to stay there mentally, which I’m very proud of. Let’s see what’s coming tomorrow."

Sinner produced a series of sensational shots against Zverev, despite limping at times, to get the better of the 2021 champion for only the second time in six attempts.

And he will now face home favourite Frances Tiafoe in the final, with the American overcoming Holger Rune in the last four.

And Sinner added: "Sometimes you have to play a bit with the gut feeling. And I think this today was my strength.

"[There were] some ups and downs, which can happen, especially when you play for more than three hours. It was a good match, I think for both of us. He served very, very well, so I can be very proud.

"[It was] a tough match, an exciting match. [The] atmosphere has been amazing throughout the whole match. Many, many different conditions. We started off with it sunny, then after came the rain.

"Now it was night session, so we had a lot of tension for both of us. I'm very happy about this performance, and obviously very happy to be in the final."

Sinner is among the favourites to taste victory at Flushing Meadows next month after defeating Daniil Medvedev in the Australian Open final. But the Italian has never gone beyond the quarter-finals in New York.

However, his victory over Zverev in Cincinnati could hand him a huge psychological boost if the two players meet again in the final Grand Slam of the year.

Sinner was knocked out of the US Open by Zverev at the fourth round stage in 2021 and 2023 after the German had reached the final in 2020.