Third-seeded Richard Gasquet of France reached his second semi-final of the season after beating countryman Julien Benneteau 6-1 4-6 6-1 at the Open Sud de France in Montpellier on Friday.
Gasquet will take on Jarkko Nieminen of Finland, who advanced to the last four with a scrappy 4-6 6-3,7-6 (2) win against Sergiy Stakhovsky of Ukraine, with both players dropping serve three times.
The sixth-seeded Benneteau needed lengthy treatment to his back early into the third set and was clearly impeded afterwards.
He barely moved to try to reach Gasquet's passing shot down the line on match point.
Michael Llodra and eighth-seeded Benoit Paire also won their quarter-finals and will meet in Saturday's other semi to guarantee a French finalist.
Llodra hit 11 aces in a 7-6 (3) 6-1 win against Jan Hajek of the Czech Republic, while Paire beat fourth-seeded Gilles Simon 7-5 7-6 (4) in another all-French match.
'It's not easy to play a friend, we were both very tense on the court,' said Paire, who also reached his second semi-final this year after reaching the last four in Chennai, India.
'I'm happy that I managed to stay focused on my match.'