Carlos Alcaraz saw his reign as US Open champion ended by Daniil Medvedev as the Russian set up another New York final against Novak Djokovic.
The Spanish top seed lost 7-6 (7-3) 6-1 3-6 6-3 to Medvedev, ensuring there will be no repeat of the Wimbledon final between Alcaraz and Djokovic.
Djokovic swatted aside young American Ben Shelton to move within one more win of a record-equalling 24th major title.
The Serb, 36, won 6-3 6-2 7-6 (7-4) to close in on Margaret Court's tally.
Alcaraz, 20, stopped Djokovic at the All England Club in July and Russian third seed Medvedev, who won his sole major at Flushing Meadows two years ago, could do the same on Sunday.