Italian Simone Bolelli upset French top seed Paul-Henri Mathieu 7-6, 4-6, 7-6 to reach the final of the Munich Open on Saturday.
The unseeded 22-year-old Bolelli took the deciding set tiebreak 7-4 to seal victory in just over three hours and set up a meeting with second seed Fernando Gonzalez of Chile in Sunday's final of the claycourt event.
Gonzalez had earlier came through another tight semi-final, seeing off the 36-year-old Moroccan Younes El Aynaoui 3-6, 6-4, 6-3 to take his place in the final.
El Aynaoui, the oldest semi-finalist in an ATP tournament since Jimmy Connors managed it at the age of 40 in 1993, was in charge at a set and a break up but he missed the chance to go 4-2 up in the second and that was the signal for Gonzalez to rediscover his form.
The Chilean levelled the match and won a long game at the start of the second set to go a break ahead before completing victory in one hour 52 minutes to reach his second final of the season.
"He played fantastic tennis," Gonzalez told reporters. "It was like being up against a top five player today."