Carlos Alcaraz marked his return to the court after four months away with a commanding 6–4, 6–4, 6–4 victory over Roman Safiullin in the 2026 US Open (ATP) first round on Monday, signaling he is ready to mount a serious threat to defend his title. Aryna Sabalenka began her bid for a historic three straight US Open titles—something not achieved since Serena Williams from 2012–14—with a 6–4, 6–4 victory over Camila Osorio, hitting back at critics after weeks of difficulty. Meanwhile, Stefanos Tsitsipas delivered the round's biggest shock, upsetting tenth-seeded Arthur Fils 7–6 (6), 7–6 (3) in a career-defining win. On the men's side, No. 8 seed Ben Shelton recovered from a dismal opening set to beat Tallon Griekspoor 1–6, 6–1, 7–6 (3), 6–2.
British qualifier Harriet Dart also advanced, ending a 19-month wait for a Grand Slam win after coming from a set down to beat Peyton Stearns. Naomi Osaka made a memorable debut at the tournament, channeling Allen Iverson as she defeated Anastasia Zakharova 7–6 (6), 7–6 (3). Three-time major champion Stan Wawrinka played his final Grand Slam match, receiving an emotional send-off after losing 7–6 (4), 7–6 (3), 6–0 to Matteo Berrettini. Meanwhile, Novak Djokovic's quest for a 25th major title ended in disappointment, though he shared a message on social media promising to keep pushing forward. The 2026 US Open (WTA) and 2026 US Open (ATP) continue into the coming week with main-draw action ramping up across both draws.