Adrian Mannarino defeated Tallon Griekspoor 7–5, 6–4, 6–0 in the first round of the US Open on hard court, an upset victory against the pre-match favourite. Griekspoor entered as the odds-on favourite at 1.65, but Mannarino's composed display across all three sets proved decisive, with the Frenchman taking control progressively through the match and delivering a dominant third set to seal the win in straight sets. The result marks a significant scalp for Mannarino early in the tournament and demonstrates his ability to compete at the highest level despite longer odds. Mannarino advances to the second round with momentum on his side.