Italian fifth seed Andreas Seppi ended hopes of an all-French final at the Metz ATP event when he knocked out Gael Monfils 3-6, 6-1, 6-4 in the semi-finals on Saturday.
Monfils was returning to the circuit this week after a four-month injury absence, but ran out of steam against the dogged Italian.
French top-seed Jo-Wilfried Tsonga will face Seppi in Sunday's final after defeating Russian veteran Nikolay Davydenko 6-0, 3-6, 6-4.
"I am happy about being in the final again here. I am rather positive about my game," said defending champion Tsonga.
"It's always been tough against Andreas. It will be a difficult match. He is very solid and playing very well lately so I will prepare myself for a big fight."