Richard Gasquet defeated Robin Soderling 4-6, 6-3, 6-3 to set up an all-French semi-final against Arnaud Clement at the Lyon International on Friday.
Another Frenchman, Marc Gicquel, reached the last four with a 7-5, 1-6, 7-6 upset win over compatriot Sebastien Grosjean .
Fourth seed Gasquet, who is the highest seed left in the tournament following the exits of Marcos Baghdatis, Gaston Gaudio and Dominik Hrbaty, was overpowered by Soderling in the first set but came back strongly.
"Until 6-4, 2-2, I couldn't find a solution. When Soderling is hitting the ball like that he is on par with Roger Federer, even if he is less talented, of course," the 20-year-old Frenchman said.
"My returns of serve were better afterwards and he seemed to tense up."
Clement, winner of the event in 2000 but now ranked 50th, outwitted eighth seed Nicolas Almagro of Spain 6-3, 6-2.
In the other semi-final, Gicquel will face seventh seed Xavier Malisse. The Belgian beat American Robby Ginepri 6-4, 6-3.
"It's my best performance since I reached the fourth round of the U.S. Open," said Gicquel, who was beaten by world number one Federer at Flushing Meadows.
Sixth-seed Grosjean served for the match at 5-4 in the second set but the 61st-ranked Gicquel broke his serve.
Having squandered a match point at 6-5, Gicquel produced a service winner to seal victory in the tiebreak on his fifth attempt.