World No. 2 Carlos Alcaraz overcame Reilly Opelka 6-4, 7-5, 6-4 under the Arthur Ashe Stadium lights to book a second-round meeting with Italy’s Mattia Bellucci. The straight-sets win extended the 22-year-old Spaniard’s streak of opening-round victories at majors to19 and kept alive his bid for a second title in New York. Home support was not enough for 45-year-old Venus Williams, who fell 6-3, 2-6, 6-1 to 11th seed Karolina Muchova in what could be her final appearance outside the United States. Williams, competing in her 25th main-draw singles campaign at Flushing Meadows, said returning healthy to the court had been her chief goal this summer. The biggest shock of the tournament’s opening days came when Australian Open champion and sixth seed Madison Keys committed 89 unforced errors and was ousted 6-7 (10), 7-6 (3), 7-5 by Mexico’s Renata Zarazua after more than three hours. Canadian teenager Victoria Mboko, fresh from winning the National Bank Open, also exited as Barbora Krejcikova prevailed 6-3, 6-2. Several leading contenders advanced comfortably. Defending women’s champion Aryna Sabalenka dispatched Rebeka Masarova 6-3, 6-2, while 2021 champion Emma Raducanu collected her first US Open victory in four years by routing Japan’s Ena Shibahara 6-1, 6-2. The early results leave Alcaraz and Sabalenka on course for deep runs, but the departures of Keys and Williams ensured that upsets and sentiment have already shaped the season’s final Grand Slam.