Montreal’s Felix Auger-Aliassime, the No. 12 seed, joined fellow Canadian Leylah Annie Fernandez in the U.S. Open semifinals on Tuesday after his opponent Carlos Alcaraz of Spain retired in the second set.
The 21-year-old Auger-Aliassime was up 6-3, 3-1 when 18-year-old Alcaraz waved over his trainer before calling an end to his tournament.
Alcaraz says he stopped playing because of an issue with a muscle in his right leg.
Medvedev, a 25-year-old from Russia, earned a spot in the final four at Flushing Meadows for the third consecutive year by stopping the surprising run of Dutch qualifier Botic van de Zandschulp 6-3, 6-0, 4-6, 7-5.
WATCH | Auger-Aliassime advances to semifinals:
The No. 2 seed from Russia dropped a set for the first time in the tournament but recovered to keep alive his bid for a first Grand Slam title.
Medvedev got close in 2019, falling to Rafael Nadal in a fifth set at Flushing Meadows, before losing to eventual champion Dominic Thiem in last year’s semifinals.