Jannik Sinner and Carlos Alcaraz navigated through their shaky starts in the US Open's first round on Tuesday, setting the stage for a potential semifinal encounter. World No. 1 Sinner rallied from a set and a break down to overcome Mackenzie McDonald, ranked 140th, in his first appearance since a doping test scandal. Alcaraz, the third seed and reigning champion in New York, shook off a hiccup in the second set to dispatch 186th-ranked qualifier Li Tu of Australia 6-2, 4-6, 6-3, 6-1. Sinner, from Italy, secured a hard-fought 2-6, 6-2, 6-1, 6-2 victory over McDonald at Arthur Ashe Stadium, dominating the latter part of the match by winning 18 of the last 22 games. The 23-year-old was back on court just a week after it emerged he had failed two drug tests in March but avoided a long suspension as officials ruled he was not responsible for the presence of the banned substance clostebol in his system.

"The support from the fans has been tremendous, especially after the news broke, even during practice sessions, there was a lot of encouragement," Sinner commented. "It's still a bit challenging. You just have to take it day by day." Alcaraz, who claimed his first Grand Slam title in New York in 2022, faced Tu in the night session, who had yet to win a main tour match this year. Despite a shaky start, Tu managed to entertain the crowd and evened the match at one set all. However, Alcaraz quickly regained control, extending his winning streak in Grand Slam matches to 15.

"He caught me off guard a bit. Initially, he seemed nervous, but he improved and played excellent tennis afterwards," Alcaraz remarked. Meanwhile, fifth-seeded Daniil Medvedev, who thwarted Novak Djokovic's bid for a calendar Grand Slam at the 2021 US Open, advanced with a four-set win over Dujan Lajovic. Stan Wawrinka, the 2016 champion, was unable to become the third man in the past 50 years to win a main draw match at the age of 39 or older, falling to Italian qualifier Mattia Bellucci 6-4, 7-6 (7/5), 6-3. In the women's draw, former champions Bianca Andreescu and Emma Raducanu were eliminated, losing to sixth-seeded Jasmine Paolini and Sofia Kenin respectively. Britain's Dan Evans triumphed over 23rd seed Karen Khachanov in the longest match in US Open history, a grueling five-hour, 35-minute marathon.