On Tuesday, American Frances Tiafoe made it to the U.S. Open semifinals for the second time in three years after Bulgarian player Grigor Dimitrov retired because of a leg injury, with the scoreline reading 6-3, 6-7(5), 6-3, 4-1 in Tiafoe’s favor.

Tiafoe is set to face 12th seed Taylor Fritz in an all-American showdown, as both are looking to end a 21-year drought for U.S. male players in major tournaments, especially with many of the top contenders having already exited early from the competition.

Dimitrov, the ninth seed, had to withdraw during the fourth round at Wimbledon against Daniil Medvedev earlier this year due to a groin issue. He left after the third set for medical assistance and continued to play through the pain as his team suggested he retire.

Tiafoe’s celebration was subdued as he embraced his opponent at the net while the audience began to leave Arthur Ashe Stadium.

“It was a very high-level match,” Tiafoe remarked. “I certainly didn’t want to finish it this way.”

Tiafoe played exceptionally well, breaking his opponent with an expertly placed backhand winner in the fifth game, and secured another break on the fourth set point when Dimitrov sent a forehand into the net.

Tiafoe looked ready to dominate when he surged to a 4-1 lead in the second set, but Dimitrov fought back, breaking the American’s serve in the seventh game as Tiafoe’s unforced errors began to increase.

Dimitrov made a strong comeback in the tiebreak, winning four consecutive points to lead 6-3, yet almost lost his advantage with a couple of double faults. Tiafoe ultimately gave away the tiebreak with a double fault on set point.

While down a break in the third set, Dimitrov winced after making a awkward step along the baseline during the final game, and a double fault allowed Tiafoe to take that set 2-1.

Dimitrov then hobbled off the court for physiotherapy before the fourth set, shaking his head as he struggled to stay mobile during the initial game of the final set.

Tiafoe, seeded 20th, is preparing for the biggest match of his career against Fritz and hopes to come out on top against another American, after a thrilling five-set victory over Ben Shelton in the third round.

“I’m incredibly excited,” Tiafoe expressed. “Although we are both Americans, I hope everyone roots for me this coming Friday.”