Swede Robin Soderling moved closer to a second Lyon title when he reached the final by beating local favourite Gilles Simon 5-7, 6-3, 6-3 on Saturday.
Seventh seed Soderling, who won the indoor event in 2004, will face unseeded Julien Benneteau in Sunday's final after the Frenchman upset compatriot Jo-Wilfried Tsonga 7-6, 7-5.
Soderling, who had knocked out top seed Andy Roddick in the quarter-finals, relied on his devastating forehand and showed more composure at crucial moments to down fourth seed Simon.
The first set was tight until the 11th game, which Simon won to love to capture his opponent's serve before wrapping up the set.
Soderling reacted by breaking the Frenchman straight away in the second set but Simon broke back immediately.
The Swede then received treatment for a blister under his left foot, broke Simon again to move 3-1 up and stayed on top until taking the second set courtesy of an unforced error from his opponent.
Another early break set up Soderling in the decisive set. He then remained in control until earning two match points on Simon's serve. The Frenchman saved the first but Soderling sealed victory with a powerful forehand volley on the second.
The second semi-final was tight but Australian Open runner-up Tsonga, seeded third here, hurt his chances with clumsy unforced errors.
Tsonga lost the first set tiebreak and was broken at the worst possible moment in the second, Benneteau capturing his serve with a crisp volley on match point.