Gaston Gaudio edged out Spaniard Guillermo Garcia-Lopez in a three set semi-final thriller at the Estoril Open claycourt tournament on Saturday.
The French Open champion won 6-4, 2-6, 6-2 and will face Tommy Robredo in Sunday's final after Carlos Moya retired from their semi-final encounter.
Moya was suffering from a shoulder injury that hampered his serve and quit when trailing 3-6, 0-3.
The 1998 French Open champion and former world number one is a doubt for next week's Rome Masters Series.
He said: "It's a big issue. I have been having trouble with my shoulder for a long time but not like it is right now."
Argentina's Gaudio was pleased to scrape through against Garcia-Lopez in a match that seemed to be running away from him.
"He was playing pretty well in the second set -- so much better than me. He was going for it and I was playing too far back and just running around and not doing anything," he said.
Gaudio, the world number five and winner of two claycourt tournaments already this year, is expecting a stern battle against Spain's Robredo.
Gaudio said: "He was injured for a couple of weeks and was desperate to come back and will be playing with all his power to win the title."
In the women's singles, second seed Dinara Safina of Russia vowed to sack coach Lars Wahlgren after she was humiliated 6-1 6-1 by claycourt novice Li Na in the semi-final.
Li will face qualifier Lucie Safarova of the Czech Republic in the final after the youngster beat third seed Gisela Dulko of Argentina 7-6, 6-0.
The number two seed Safina held serve only once and made a string of unforced errors as she succumbed to Li, the fourth seed who had not played on clay since she was a child.
Safina prowled around the court in obvious discontent, frequently yelling out loud to try to spark her game into life.
After the match she said it was time to return to Russian coach Alexander Zlatoustov who parted company with Safina after the Australian Open in January.
She said: "After the Australian Open, my Russian coach broke up with me because I wasn't listening to him. My agents offered me Lars and I said yes because I needed a coach."
It has not worked out with the Swede, however, and Safina says her game is going backwards.
"We are not working on what I need to improve," she said. "I need to work on my serve and my forehand and I need to work to improve but I'm not improving, I'm getting worse."