France’s Gael Monfils celebrated his 40th birthday with a fourth-round victory at the US Open on Tuesday, marking a notable milestone in his final season on the professional tennis circuit. The veteran player, participating in his 18th US Open and his 70th Grand Slam tournament, defeated Paraguayan Adolfo Daniel Vallejo 2-6, 6-1, 6-2, 6-0 to advance to the second round.

Monfils began the match with a slow start, dropping the first set to the 22-year-old Vallejo, who was making only his third Grand Slam appearance. However, Monfils quickly regained his rhythm and dominated the next three sets, showcasing his trademark athleticism and flair. During the final set, he celebrated a winning shot with an exuberant leap, earning enthusiastic applause from the New York crowd.

The atmosphere turned festive as the spectators spontaneously joined in an "Happy Birthday" tribute to Monfils following his win, underscoring his popularity and the significance of the occasion. “You guys always make it electric, amazing,” Monfils said during his on-court interview. “Let’s keep it going for the second one.”

Monfils, who reached a career-high ranking of sixth in 2016 and made it to the US Open semifinals that same year, is currently ranked 311th. His participation in the 2026 season has been limited to only a few tournaments as he prepares for retirement at the end of the year.

His victory at the US Open also made him the oldest man to win a main-draw match at the tournament since Jimmy Connors accomplished the feat in 1992, coincidentally also on his 40th birthday. Reflecting on the milestone, Monfils expressed pride in his performance, calling it one of the top birthdays in his life.

The match highlighted the contrast between the seasoned Monfils and the young Vallejo, representing different stages in their professional careers. Monfils’ blend of experience and showmanship captivated the crowd, while Vallejo’s early success in the first set indicated his potential on the big stage. The win sets Monfils up for a second-round appearance in what many expect to be his farewell US Open appearance.