World No. 1 Carlos Alcaraz finished off an exhausted Alexander Zverev 6-3, 6-2, 6-4 on Wednesday to move into the U.S. Open semifinals where he will take on Daniil Medvedev in an intriguing clash featuring the last two champions at Flushing Meadows.

Three-time champion Novak Djokovic and 20-year-old Ben Shelton booked their spots on Tuesday.

There were questions about how prepared Zverev would be to face the energetic Alcaraz after playing the longest match of the tournament ¡ª a nearly five-hour, five-set marathon against Jannik Sinner in punishing conditions on Monday.