Stefano Tsitsipas ended his Grand Slam season with a five-set loss to a Swiss qualifier on Wednesday as Dominik Stricker produced the biggest upset of the US Open with his defeat of the seventh seed.

The 2020 Roland Garros junior champion scored a breakthrough first Top 10 win of his career, taking just over four hours to stun the Greek as he broke as Tsitsipas served for the match leading 5-3 in the fourth set.

That feat left the seed struggling as Stricker stayed alive to level at two sets each in a tiebreaker.

The No. 128 broke early in the deciding fifth set and held the margin as he sent a forehand winner down the line on his first match point to seal the upset.

“I’m a bit speechless,” the 21-year-old from Bern said. “I came back in the fourth set, but I don’t know how I did it.

“I just kept playing high-level tennis. This is a great day. The crowd really helped me through a tough battle, I’m super happy.”

Tsitsipas has been on a downward trend throughout the season at the majors. Greek media later reported that he had announced his split from Greek-Australian coach Mark Philippoussis.

“I felt like I was out of rhythm – My partnership with Mark is over”

Tsitsipas began 2023 with an Australian Open final, but dropped to the quarters at Roland Garros and a Wimbledon fourth round before his New York exit in his second match.

Tsitsipas still took his upset loss in stride: “My opponent showed better tennis than I did, I want to congratulate him.

“I consider myself a good player, and I don’t want to be a person that can be beaten easily.

“I try to make it as hard as I can, and if it doesn’t work I move on with my life.”

Meanwhile, second seed Novak Djokovic motored ahead, earning a 6-4, 6-1, 6-1 victory over outclassed Spaniard Bernabe Zapatas Miralles in less-than-ideal conditions.

The Ashe court match was played in humidity after morning rain, with Djokovic glad to be done with the day’s work.

While the Serb who will take back the No. 1 ATP ranking when the tournament ends was not pleased with his start, things quickly improved even as he had to play an early day match after a late-nighter less than 48 hours earlier.

“There was a lot of humidity and you could feel it on the court. But it’s the same for both players so you just accept it.

“I didn’t start the match very well but the second and third sets were a few notches higher.

“I’m pleased with how it ended.”

The three-time champion added: “You can’t always play in ideal conditions, But once the event starts, you need to be ready – or at least tell yourself that you are.

“I can still play better, but I’m happy to be back and playing here in New York.

“I still have the hunger to play my best on this court.”

2020 titleholder Dominic Thiem suffered a setback as the Austrian retired with a stomach upset. He handed over a 7-6 (1), 1-0 to American Ben Shelton. 

Main photo:- Dominic Stricker celebrates beating Stefanos Tsitsipas – by Roger Parker International Sports Fotos Ltd