Six-time champion Roger Federer will play Alejandro Falla in the final of the Gerry Weber Open after they won their semi-finals on Saturday.

Federer fired 10 aces and defeated fourth-seeded Kei Nishikori 6-3, 7-6 (4) as he improved his record here to 45-5.

Nishikori rallied to force the second set to the tiebreak, where he made a mini-break at 4-2, only to let Federer off the hook with two consecutive forehand errors.

After a first-round bye, Federer began his Wimbledon preparations by defeating Portugal's Joao Sousa on Thursday and then had a walkover in the quarter-finals.

Falla rallied to beat 2011 champion Philipp Kohlschreiber 5-7, 7-6 (5), 6-4 to become the first Colombian to reach the final of a grass-court tournament.

"It's an amazing feeling," Falla said. "I knew I had good chances here. I already played great matches on grass courts. It's my favorite surface."

The 69th-ranked Falla saved six of the nine break points he faced before defeating Kohlschreiber in 2 hours, 21 minutes. "He took the big points and that makes the difference," Kohlschreiber said.

Sunday's final against seven-time Wimbledon winner Federer will be Falla's second on tour after he finished runner-up to Ivo Karlovic at Bogota in 2013.
"It would be nice to play Roger, maybe to get revenge for the last couple of matches on grass at the Olympics and at Wimbledon," Falla said, referring to their previous meetings in 2012 and 2010.

Federer has a 100 percent record from six meetings with Falla.

Federer, who made his debut at the tournament 14 years ago, will be playing for his 79th title and his seventh from 12 appearances in Halle.