Top-seeded Jannik Sinner triumphed over Mackenzie McDonald in the first round of the U.S. Open, recovering from a poor start to win 2-6, 6-2, 6-1, 6-2. This match marked Sinner's return to competition following revelations of two positive doping tests for clostebol, from which he received no suspension after an independent tribunal ruled he bore no fault. Despite an initial struggle, including 14 unforced errors in the first set, Sinner regained his form and dominated the remainder of the match, hitting 38 winners and capitalizing on McDonald's errors. Sinner expressed relief at the crowd's positive reception and emphasized his focus on improving for the next round. He will face Alex Michelsen in the second round. This victory also marked Sinner's first win at Arthur Ashe Stadium.