Carlos Alcaraz beat Jannik Sinner in a thrilling match between two young players to reach his first grand slam semifinal.
This was the latest match ever to end at the US Open.
After five hours and 15 minutes of hard tennis, Alcaraz finally won 3-6, 7-6 (7), 7-6 (0), 5-7, 6-3 at 2:50 a.m., setting up a match with Frances Tiafoe on Friday.
Three matches had already ended at 2.26am, but this was the second time in a row that Alcaraz had played past 2am.
His win over Marin Cilic in the fourth round ended at 2.23am. The 19-year-old saved a match point in the fourth set
and came back from a break down in the deciding set to show once again what a special talent he is.
He could still leave New York as world No. 1, but this match showed that men's tennis doesn't need to be afraid of a future without its ageing superstars.
Fans who stayed until the end cheered Alcaraz on loudly, and he said, "I still don't know how I did it.