French veteran Gael Monfils celebrated his 40th birthday with a dominant straight-sets triumph over Paraguay's Adolfo Daniel Vallejo at the US Open, winning 2-6 6-1 6-2 6-0 to become the oldest man to claim a main-draw victory at the tournament in over three decades. The milestone achievement carries particular weight as Monfils has signalled this will be his final appearance at Flushing Meadows before retiring from professional competition.

American prospect Coco Gauff advanced past her opening match by defeating Turkey's Zeynep Sonmez 6-3 6-4, conquering a year-long struggle with serving mechanics that had previously undermined her performance and resulted in an early tournament exit. With her once-troubled serve now operating as a key strength rather than a weakness, the 22-year-old demonstrated renewed composure on court and the mental resilience required to overcome the technical setback.