US Open: Is men's singles victory a formality for Alexander Zverev or will Ben Shelton, Frances Tiafoe or Karen Khachanov trouble him?

Shelton sent defending champion Carlos Alcaraz packing in the early ‌hours of Wednesday with the pair slugging it out in the latest-finishing match in tournament history as he reached his third major semi-final, having made the final four in the 2023 US Open and 2025 Australian Open.

"That was a war," said Shelton. "The most enjoyable match that I've had in my career."

Tiafoe recovered from two sets and ‌a break down to beat compatriot Alex Michelsen, reaching the semi-finals for a third time in a thrilling fightback.

The American has provided treasured memories ​for the home fans in New York, from his dragon-slaying defeat of Rafael Nadal en route to the 2022 semi-final, ​to his blockbuster win over compatriot Shelton two ‌years ago.

But the Cincinnati runner-up this year is ready to write a new chapter this time ​around, saying: "I'm just a different person in general. Those two runs (to the semi-finals) were great, ​something I will cherish forever, but I'm not that person ⁠who I was when I made ⁠one in 2022 and when I made one in '24. I'm not that person. I'm excited to see what this ‌me does," said Tiafoe.

"I have higher hopes for myself. So yeah, it's great. The tournament ‌is still going. There's a lot more tennis to be played, a lot more sets to be played, and a lot more physical things to be done. We're going to enjoy this, but we got to keep going."

Tiafoe is enjoying a career resurgence having undertaken a big lifestyle change and fitness regime towards the end of last year.

Former world No 1 Lindsay Davenport said: "If you hear their stories about last fall, and what a dark place Frances was in, he was willing to turn over, to try and give it his best shot.

"It's not easy sometimes for players or people to do that, but he has kind of shifted everything in his life to revolve around tennis.

"Now to watch him be able to go out there and compete from two sets down, like the old Frances doesn't necessarily (do), to stick his heels in and be like 'I'm not going anywhere' - I mean, he's fighting."

While the men's draw has fallen to pieces in the absence of Jannik Sinner and with Novak Djokovic and Alcaraz falling by the wayside, Alexander Zverev has been quietly going about his business.

Luciano Darderi, the 21st seed, is the highest-ranked player Zverev has faced, while he eased past world No 70 Botic van de Zandschulp in straight sets .

The 29-year-old is a big favourite to beat unseeded Russian Karen Khachanov in the opening semi-final on Friday from 8pm on Sky Sports Tennis .

Zverev has beaten Shelton in all five of their career meetings and has lost just one of his 10 matches against Tiafoe.

Having won his first Grand Slam title at this year's French Open and then reached the Wimbledon final, the world No 2 should be feeling at home in the latter stages of major tournaments.

But he said: "I think the more often that you get to that stage, the more normal it becomes, which is something that you should never take for granted.

"I know it can change in a heartbeat in tennis. I think confidence is something that is incredibly important, but also can go away quite quickly.

"I found that out after Wimbledon where I didn't play well throughout the two tournaments on the hard courts, and then I found it again here.

"But yeah, of course I'm happy with how things are going, but looking forward, I still hope to play two good matches here."

Khachanov is seeking his first major final having reached the semi-finals of the US Open in 2022 and the Australian Open in 2023.

Khachanov was unseeded in a Grand Slam tournament for the first time since 2018 after a strange season.

He reached at least the third round of all four majors for the first time but is just 10-15 in other events, with losses in the opening rounds of all three hard-court events before coming to New York.

Zverev and Khachanov, both in the 1990s generation, have met nine times, with ​the German holding a 6-3 edge.

Their most notable encounter came in the 2021 Tokyo Olympics final, when ⁠Zverev won in straight sets to take gold, while their only previous Grand Slam meeting came at the French Open in 2018, when Zverev fought back from a set down to win in five.

The US Open is live on Sky Sports from August 30. Stream tennis with no contract on NOW and the Sky Sports App . You can also watch the Laver Cup at The O2 in London from 25-27 September live on Sky Sports.