NEW YORK (AP) — Defending champion Naomi Osaka advanced to the third round of the U.S. Open on Wednesday when her opponent withdrew because of illness.

Simona Halep and Garbiñe Muguruza also reached the third round, ending long absences in Flushing Meadows for the two-time Grand Slam champions.

They were two of the few players to squeeze in victories early on a rainy afternoon, when play started late and then was suspended briefly on the outer courts.

Osaka had been scheduled to face Olga Danilovic of Serbia in the first match of the day at Arthur Ashe Stadium. Instead, the U.S. Tennis Association moved the 12th-seeded Halep’s match against Kristina Kucova into that spot.

Halep won 6-3, 6-1 to reach the third round for the first time since a quarterfinal appearance in 2016. She was knocked out in the first round in both 2017 and 2018.

The ninth-seeded Muguruza got past the second round of the U.S. Open for the first time since 2017 when she beat Andrea Petkovic 6-4, 6-2.

Theirs were two of the only matches to start on time on a day when heavy rain was expected in the New York area. Puddles filled the grounds around the Billie Jean King National Tennis Center, though rain had stopped as fans began to enter for the day session.

The outside courts were empty while they were being dried so play could eventually start.

Once they did, fifth-seeded Elina Svitolina beat Rebeka Masarova 6-2, 7-5, and No. 20-seeded Ons Jabeur raced to a 6-0, 6-1 victory over Maria Camila Osorio Serrano in 53 minutes.

Most other players on the outer courts had to wait out another delay during their matches, as fans raced for cover when rain returned.

Osaka would have been going for her 17th straight victory in a Grand Slam match. After missing Wimbledon during a mental health break, she returned to the majors with a 6-4, 6-1 victory over Marie Bouzkova on Monday night.

The two-time U.S. Open champion hasn’t lost a Grand Slam match since Coco Gauff beat her at the 2020 Australian Open.

Danilovic wrote on Instagram that she was dealing with a viral illness unrelated to COVID-19.

The 17-year-old Gauff was set for one of the featured matches of the day, facing 2017 U.S. Open champion Sloane Stephens under the lights at Ashe.

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