Jannik Sinner admitted that his 5-hour 15- minute US Open defeat to Carlos Alcaraz will “hurt for a while”.

The 21-year-old Italian squandered a match point in the fourth set to lose 6-3, 6-7 (7/9), 6-7 (0/7), 7-5, 6-3 in a quarter-final that ended at 2:50 a.m. Thursday.

It was the second-longest US Open match ever and surpassed the previous record for latest finish of 2:26 a.m., set three times.

The record for the longest match is 5:26, set by Stefan Edberg and Michael Chang in 1992.

“I had some tough losses, for sure. This is in the top list,” said Sinner.

“I think this one will hurt for quite a while. But when I wake up, I will try to somehow take only the positives.

“But it’s tough, for sure. Maybe next time I can win this.”

It was Sinner’s fourth Grand Slam quarter-final defeat — three of them have come this year.

At Wimbledon, he was two sets up on Novak Djokovic before being beaten.

At the Australian Open, he was beaten in straight sets by Stefanos Tsitsipas.

“The first week here I didn’t play my best tennis, for sure,” added Sinner, the world number 13.

“But today I raised it because he’s the kind of player who makes you raise the level.”