Caroline Garcia overcame a dreadful start to beat Kristyna Pliskova in straight sets at the Internationaux de Strasbourg and remain on course to defend her title.
Garcia, the fifth seed and highest-ranked player left in the competition, has yet to drop a set this week, but appeared highly likely to do so after losing the first four games against Pliskova on Thursday.
However, the Czech twice failed to serve out the opener - spurning six set points - and Garcia triumphed 7-6 (7-3) 6-2 to set up a semi-final meeting with Daria Gavrilova.
Gavrilova, who edged out Ashleigh Barty 6-4 6-7 (3-7) 7-6 (7-5) in her last-eight match, got the better of Garcia when the two met in Rome last week.
"I did some stupid mistakes, but also I know she can have some ups and downs. I will just try to play my game and be aggressive," said Garcia ahead of their rematch.
The other semi in Strasbourg will see Sam Stosur take on Peng Shuai after they triumphed in straight sets against Carla Suarez Navarro and Shelby Rogers respectively.
At the Nurnberger Versicherungscup, top seed and defending champion Kiki Bertens beat Alison Riske 6-4 6-3 to reach the last four and will now face Misaki Doi, who was the beneficiary of Yaroslava Shvedova's retirement after one set.
Qualifier Barbora Krejcikova beat Carina Witthoeft in a third-set tie-break, but must wait to find out her semi-final opponent. Second seed Yulia Putintseva and Sorana Cirstea will complete their last-eight tie on Friday, the pair having been locked at 4-4 in a gruelling final set when darkness forced a postponement.