Ben Shelton clinched the biggest win of his career as he defeated defending champion Carlos Alcaraz in a five-set epic stretching deep into the New York night to reach the semi-finals of the US Open. 

The American prevailed 6-7 (5-7) 6-1 6-1 1-6 7-6 (10-7) to reward a raucous Arthur Ashe Stadium crowd gripped until 3.33am in what was the latest-ever finish to a US Open match.

It marked Shelton's first career win over a top-three player, against which he had been 0-17 coming into the match.

Shelton will now play Frances Tiafoe in the final four after his fellow countryman's thrilling five-set victory over Alex Michelsen earlier in the evening.

"For me it's always about the people in the crowd, whether it's my coaches, team or friends and family, or the city of New York that showed up tonight until 3am with the USA chants, that's what kept me going and what got me this win," Shelton said on-court.

"It's incredible. This is the greatest sports city and greatest stadium in the world. I'm hoping my best friend and sister don't have to be at work at 6am.

"I'm so grateful, so blessed to be in front of you guys and share the court with Carlos is an absolute honour."

More to follow...

Frances Tiafoe recovered from two sets and ‌erased a 0-3 deficit in the fifth set to beat American compatriot Alex Michelsen 5-7 3-6 7-5 6-3 7-6 (10-6), reaching the semi-finals for a third time.

The 11th seed ​appeared to have lost all the magic of his early campaign before claiming the momentum in the third set and clinching ​it with a forehand winner to the deafening cheers of ‌the fans on Arthur Ashe Stadium.

Michelsen had flown under the radar in his deepest major run but ​earned respect on the biggest stage of American tennis with 21 aces, and Tiafoe cut his own celebration short to comfort the 22-year-old in an emotional ​embrace.

"I hope he gets tight," Tiafoe said of his mindset at 4-5 down in the third set. "He gave me some gifts, a couple of double faults there.

"But then I slowly started to get my rhythm there, snuck out the third set and slowly started playing better and better.

"He is a hell of a player. He should've easily won today, so shout out Alex Michelsen."

Tiafoe joined Andre Agassi as the only American men to reach three US Open semi-finals in this century and will return to the top 10 for the first time in three years in the rankings.

"Everyone was sleeping in the first couple of hours and I was asleep with you all," Tiafoe joked following his win.

"As it went along, the energy was incredible, as always. Thank you [to the crowd] for being there for me. I really appreciate that."

Sky Sports Tennis' Laura Robson:

"You can't help but feel sorry for Alex Michelsen considering how close he was and we all know Frances is a fan favourite in this situation.

"The tears started coming from Michelsen. It was like a punch in the gut for me and I don't even know him.

"Having been in these situations when you're so close to the finishing line and you know it's on your racket, I think that's the worst feeling. You know that you kind of did choke a little bit. That's the absolute worst.

"Brutal day for him but you have to tip your cap to Frances for turning that match around."

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.