Russian veteran Nikolay Davydenko stunned top seed and Spanish world number five David Ferrer 6-2 6-3 to reach the Qatar Open final.
The 31-year-old, who beat Rafael Nadal in the 2010 final, faces second-seeded Frenchman Richard Gasquet on Saturday.
Gasquet, 26, ranked 10th in the world, beat German qualifier Daniel Brands 7-5 7-5 in one hour and 38 minutes.
Davydenko, the former world number three now ranked 44, has won 21 ATP Tour titles to Gasquet's seven.
"I have to win this final, but, yeah, it's true, I'm feeling well," said Gasquet, a former world number seven.
"I don't know what I can do this year. But on every match I will try to fight, and I will try to prepare better on Grand Slams, to win some tournaments, to start in Doha in the final, so it's important to win."