Their semifinal victories set up an all-French title match before a throng of enthusiastic tennis fans in their home country.
Gicquel had a tough time before beating Colombian qualifier Alejandro Falla, 4-6, 6-2, 7-6 (9-7), while Grosjean was an easy 6-1, 6-2, victor against compatriot Jo-Wilfried Tsonga, who is ranked 65th in the world and qualified for his first ATP semifinal.
In Sunday's final, Grosjean and Gicquel will play for a winner's check of $138,000.
The event has seen a number of seeded losers.
Among them were No. 1 Andy Roddick of the United States and second-seeded Tommy Robredo of Spain.
No. 3 Tommy Haas of Germany withdrew before the event began.