Youzhny dispatched Hanescu 6-3, 6-3 and earned a berth in Sunday's finals against Robin Haase of the Netherlands.
Youzhny narrowly missed the semis altogether, but saved three match points in his quarterfinal match against Juan Monaco. He is in position to become the first Russian to win the Gstaad tournament since 1995.
Haase needed three sets to get past fifth-seeded Feliciano Lopez 4-6, 6-1, 6-4.
"I was broken early in the first set and that's the worst thing that can happen to you against Feliciano," he said. "But I managed to fight back and I'm very happy to be in the final."