Defending champion Li Na of China shook off a tentative start to reach the French Open last 16 on Saturday with a 3-6, 6-2, 6-1 win over America's Christina McHale.
Seventh-seeded Li will face Kazakh qualifier Yaroslava Shvedova for a place in the quarter-finals.
The 30-year-old Li had to draw upon her 10-year age gap to prevail over the 36th-ranked American, who had fallen in the first round at Roland Garros in 2010 and 2011.
Li, struggling with her serve and backhand, was broken twice in the first set as McHale put up a robust defence.
Li found her form in the second set, breaking McHale in the fourth game with a well-timed drop shot that the American returned wide and earning another break in the eighth game by forcing McHale into errors.
The third set was all Li, who broke the now exhausted McHale twice and finished the match with a clean forehand winner.
Age was in Li's favour the longer the match lasted, giving the Chinese a chance to use a variety of shots to find gaps in McHale's game in bright sunshine at Suzanne Lenglen court.