Frances Tiafoe secured a spot in the US Open semifinals for the second time in three years after his quarterfinal opponent, Grigor Dimitrov, retired due to an injury during the fourth set on Tuesday night. Tiafoe was leading 6-3, 7-6 (5), 6-3, 4-1 when Dimitrov made the decision to stop playing.
Dimitrov, who had previously played a grueling five-set match in the fourth round, began showing signs of physical distress late in the third set against Tiafoe. He was seen clutching at his left hamstring and moving cautiously between points. Following the third set, Dimitrov received medical attention from a trainer and briefly left the court for treatment.
