Top seed Camila Giorgi was beaten in three sets by Caroline Garcia at the Lyon Open on Tuesday.
Italian Giorgi battled to take the first set but was pegged back by the home favourite before her game collapsed in a 5-7 6-4 6-0 defeat.
Dominant on serve in the opening set, Giorgi failed to take either of two break points at 3-2 up in the second set. She then won only one point in three consecutive games to allow Garcia to level.
The world number 29 earned just two points on serve in a one-sided decider as Garcia set up a last-16 clash with another Italian, Martina Trevisan.
Earlier, Russian Vera Zvonareva was comfortably beaten by seventh seed Alison van Uytvanck, who could await Garcia in the quarter-finals.
Zhang Shuai beat Kristina Mladenovic 7-6 (7-3) 7-5 to secure a match with Arantxa Rus, who defeated Danka Kovinic for the loss of just two games.
The top-ranked remaining player in the draw, world number 30 Sorana Cirstea, sealed a round-of-16 showdown with Stefanie Voegele after a comfortable 6-3 6-1 defeat of Mariam Bolkvadze.