ROME • Serena Williams’ 1,000th tour-level match ended in defeat as she marked her return to action with a 7-6 (6), 7-5 loss to Nadia Podoroska on Wednesday in the second round of the Italian Open.

The eighth-seeded Williams, who hadn’t played since the Australian Open, came from a break down twice in the opening set and saved the first three set points she faced in the tiebreaker before Podoroska converted her fourth.

Defending champion Simona Halep was forced to retire while leading 6-1, 3-3 with a left calf injury in the second set of her match against fellow former No. 1 Angelique Kerber. Second-seeded Naomi Osaka is out after losing 7-6 (2), 6-2 to Jessica Pegula of the U.S. Fourth-seeded Sofia Kenin lost 6-1, 6-4 to Barbora Krejcíková. Top-ranked Ashleigh Barty and former champion Karolina Pliskova earned straight-set wins, while Vera Zvonareva ousted 11th-seeded Petra Kvitova 6-4, 3-6, 6-4.

Rafael Nadal held off local teen Jannik Sinner 7-5, 6-4. Third-seeded Daniil Medvedev lost 6-2, 6-4 to fellow Russian Aslan Karatsev.

• PLAYERS at the French Open will be allowed a daily one-hour window outside their social-distancing bubble, organizers said.