British number one Johanna Konta continued her fine clay-court season by beating American Lauren Davis to reach the French Open third round.
Konta, seeded 26th, needed four match points to clinch a hard-fought 6-3 1-6 6-3 victory over her 111th-ranked opponent.
She had never won a main-draw match at Roland Garros until her opening match of this year's tournament on Tuesday.
Konta will play Slovakia's Viktoria Kuzmova, ranked 46th, next.
The Briton would have expected to face fourth seed Kiki Bertens - who Konta beat in the Rome Masters semi-finals recently - but the Dutch player retired from her second-round match against Kuzmova because of illness.
Konta, 28, has surged back up the rankings after a productive clay-court season which has seen her reach the Morocco Open and Italian Open finals, beating the likes of Sloane Stephens, Venus Williams and Bertens in Rome.
Now she has a great opportunity to reach the second week at Roland Garros after eventually overcoming Davis.
After edging a tight opening set by breaking in the penultimate game, then losing her way in the second, Konta showed impressive mental resilience to take the decider.
The Briton managed to instantly block out losing the second set, hitting 10 winners and making just two unforced errors to surge into a 5-0 lead.
Then she stuttered again with only one game required for victory.
Davis saved the first match point on her own serve with a crunching cross-court forehand, then nicked a break back after Konta let slip a 40-15 lead at 5-2.
A hold to love for the American reinforced that momentum had swung back in her favour, and Konta's advantage looked precarious when she trailed 0-40 as Davis threatened to put the set back on serve.
Konta, however, managed to reset again, fighting back to avert danger and clinching victory at the fourth attempt with a thumping drive volley.
'She is tough mentally and has shown good composure' - analysis
Great Britain Davis Cup captain Leon Smith on Radio 5 Live Sports Extra
I am thrilled for Konta. It is tough to get over the line when sets get tight like that. It is wonderful to see. The third round is such good progress for her.
With Kiki Bertens having to retire from her match it has opened up the draw. It gives Konta a really good opportunity to get to the second week.
We have seen upsets but she is in a good way. She is tough mentally and has shown good composure.