Tommy Haas continued his spectacular run at the ATP 250 event in Halle on Saturday, beating defending champion Philipp Kohlschreiber 7-6, 7-5.
Haas has not played much tennis of late due to several injuries, but the German veteran is experiencing somewhat of a resurgence.
He will play Roger Federer for the title on Sunday.
"Tommy and I share many years together on the tour and also our families are close," Federer said of the upcoming clash. "I’m happy for him that he made it so far and beat such top players. I hoped that he’d find his way into the tournament and would have a good run. He’s very dangerous on grass. So, it won’t be an easy final for me."
Federer is a seven-time finalist at the prestigious event.