Serena Williams trailed by a set and a break at the French Open before recalibrating her shots, erasing that deficit and beating 17th-seeded Ashleigh Barty of Australia 3-6, 6-3, 6-4 to reach the third round.

Williams had all sorts of trouble in the opening set, making 12 unforced errors and only three winners. But she began putting the ball right where she wanted early in the second set, accompanying nearly every point she won with a celebratory yell and fist pump. It took about 15 minutes for Williams to take four games in a row and control of that set.

Williams broke to lead 2-1 in the third, held for 3-1, and was on her way at Court Philippe Chatrier.

The 36-year-old American is playing in her first Grand Slam tournament in 16 months — and first since giving birth to a daughter about nine months ago.

Williams has won three of her 23 Grand Slam singles titles at Roland Garros.

Williams' next opponent at the French Open will be 11th-seeded Julia Goerges.

The German player reached the third round at Roland Garros for the fourth time with a 7-5, 7-6 (5) win over Alison Van Uytvanck in the final match on Thursday's program.

Williams has a 2-0 record against Goerges, winning both matches in straight sets.