- World No 1 defeats Mackenzie McDonald in four sets
- Naomi Osaka impresses in victory against Ostapenko
Jannik Sinner returned to competition for his first match since his anti‑doping case was made public and he recovered from an early scare to defeat Mackenzie McDonald 2-6, 6-2, 6-1, 6-2 and reach the second round of the US Open.
Sinner struggled badly early on against McDonald, who is ranked No 140 and has been out of form this year, trailing by a set and a break at 2-6, 0-1. Just as the match seemed to be moving away from him, he began to turn it around. After striking 14 unforced errors in the opening set alone, Sinner finished the final three sets with just 15 unforced errors in total.