Seeded 10th in New York, Fils had entered the final Grand Slam of 2026 with high hopes, having just won the 1,000-level Masters tournament in Cincinnati around a week earlier.

But Fils, 22, fell to Tsitsipas, 4-6, 7-6 (7/3), 6-1, 6-4.

Fils began well, winning the first set and vaulting to a 5-3 lead in the second behind strong serving and his trademark heavy forehand.

But the French player tightened up when he tried to serve out the second set, double-faulting early in the game, which concluded when Tsitsipas broke serve with a blistering backhand up the line.

Tsitsipas, a former top five player who has slumped to 53 in the world, dominated the tie-breaker and continued that momentum to claim the next two sets.

Besides the ranking gap, Fils carried a 5-0 winning record against Tsitsipas heading into the match.

But Monday's contest was their first in the Grand Slam best-of-five sets format, where 28-year-old Tsitsipas has far more experience.

Tsitsipas has a middling record at Flushing Meadow, but has excelled at other slams, reaching the final of the 2021 French Open and the 2023 Australian Open, losing to Novak Djokovic both times.

Fils has missed multiple Grand Slam tournaments due to injury since emerging as a top prospect, including this year's Australian and French Opens.