Sofia Kenin moved into the semifinals of the Lyon Open after overcoming a tricky spell midway through her match with Oceane Dodin.
The Australian Open champion saved a match point against Romanian qualifier Jaqueline Cristian on Thursday but seemed to be finding some commanding form against Dodin as she eased into a 6-1, 5-2 lead.
However, the American rather meekly allowed her opponent - ranked 130 in the world - to force a second-set tie break and then threw away a 5-1 advantage as the match went the distance.
Kenin was ultimately pleased with her performance, though, after coming through 6-1, 6-7(5), 6-2 following over two hours on court.
"It was still not perfect today, but I definitely feel like I found my rhythm," she said. "I was playing well, dictating well.
"It was a bit of a strange match. I was up, and somehow managed to not close it out there, but overall, I think it was a good match. I played some good tennis, some good points, and I'm happy with the way that I found my rhythm after yesterday."
Kenin will face fifth seed Alison Van Uytvanck in the last four, with the Belgian having dispatched Caroline Garcia in an impressive 6-2, 6-2 victory.
The second semifinal will feature Russian Daria Kasatkina, who battled past Camila Giorgi in three sets, take on German Anna-Lena Friedsam, who knocked out eighth seed Viktoria Kuzmova.