Top seed Richard Gasquet comfortably reached the quarterfinals of the Open Sud de France by beating Ernests Gulbis of Latvia 6-4, 6-4, while second-seeded Marin Cilic went out to lowly ranked Alexander Zverev 7-6 (4), 7-6 (1) on Wednesday.
Gulbis, a French Open semifinalist two years ago, had nine aces compared to three for backhand specialist Gasquet. But he dropped serve once in each set and failed to create a break-point chance against the Frenchman, who next plays Cypriot Marcos Baghdatis.
Cilic, the 2014 U.S. Open champion, swapped breaks with Zverev in the first set. The 13th-ranked Cilic then missed a chance to break Zverev in the ninth game of the second set before doing so two games later.
However, the 85th-ranked Zverev broke straight back and clinched the tiebreaker with ease.
In another upset, Edouard Roger-Vasselin beat No. 5 Gael Monfils 6-4, 7-6 (5) in an all-French match, proving slightly more consistent on serve and breaking Monfils twice.
No. 8 Baghdatis advanced earlier by defeating Taro Daniel of Japan 6-2, 7-6 (7).
The 53rd-ranked Baghdatis, who won his first match this season in the previous round at the hard-court tournament, fired eight aces and broke Daniel three times.
An Australian Open runner-up in 2006 and Wimbledon semifinalist later that year, Baghdatis lost in the first round in Melbourne this year and received a wild card to play in Montpellier.
Also advancing to the last eight was Michael Berrer, who defeated qualifier Kenny De Schepper 6-3, 6-4, and next plays countryman Zverev.