NEW YORK: Defending US Open champion Aryna Sabalenka was given an early test before she moved into the second round while Emma Raducanu won her first match at the Grand Slam since her 2021 triumph as the tournament began a day earlier than usual on Sunday. Under the new extended 15-day format, first-round singles action will be contested from Sunday to Tuesday, rather than two days as in previous years, spreading out the star attractions and allowing access for another 70,000-odd spectators. Sabalenka was among the marquee names on the opening day’s schedule and the Belarusian fed off the vocal Arthur Ashe crowd to overcome determined Swiss Rebeka Masarova 7-5 6-1 and move into the next round. “When I won that first set and you cheered for me, I got goosebumps,” said Sabalenka, who will take on Russia’s Polina Kudermetova in the second round on Wednesday. “Your support means a lot to me, thank you for coming. It was an amazing atmosphere.” Novak Djokovic, the record 24-times Grand Slam singles champion, headlines the evening schedule on the main showcourt against American Learner Tien and he will be followed by 2024 finalist Jessica Pegula, who plays Egypt’s Mayar Sherif. Italian Jasmine Paolini kicks off the later program on Louis Armstrong Stadium against Australian qualifier Destanee Aiava, followed by the 2021 champion and 13th seed Daniil Medvedev, who faces France’s Benjamin Bonzi.