American sixth seed Coco Gauff (19) recovered from an error-strewn start to begin her French Open quest with a 3-6 6-1 6-2 victory over Spain's Rebeka Masarova (23) on Tuesday.
Gauff, runner-up a year ago, looked uncomfortable early on with her troublesome forehand frequently letting her down.
World number 71 Masarova, a former French Open junior champion, took full advantage to dominate the opening set and looked on course for a shock victory.
But Gauff settled down on a sunlit Court Suzanne Lenglen and reeled off seven games in a row from 1-1 in the second set to take command.
With her confidence restored, Gauff made no mistake as she moved 5-2 ahead in the decider and wrapped up victory with a hold to love as Masarova sent an attempted lob long.
She will now face Julia Grabher (26) in the next round.