Defending champion Li Na rallied from a set down to defeat American Christina McHale 3-6 6-2 6-1 in the third round of the French Open.
The seventh seed from China needed almost two hours on a sunsoaked Court Suzanne Lenglen at Roland Garros to see off the world number 36.
Li struggled with her serve in the early stages and went a break down in sixth game before immediately breaking back.
But McHale was making the most of her superior pace and broke again to take the opening set after 48 minutes.
Li upped her game in the second set, finding better angles to open up a 4-1 lead and a second break enabled her to level the match.
She then reeled off five games in a row in the decider to wrap up the victory and set up a last-16 meeting with Kazakh qualifier Yaroslava Shvedova, a 6-4 7-5 winner over Carla Suarez-Navarro.