Colombia's Alejandro Falla advanced to the semifinals of the Gerry Weber Open, a Wimbledon tune-up in Halle, Germany, with a 7-6 (7-4), 7-6 (7-2) victory Friday over Peter Gojowczyk.

In a match that was close throughout, the 69th-ranked Falla rode a better winning percentage on second-serve points to the victory and his first semifinal berth since last year's hard-court event in Bogota.

The 120th-ranked German wildcard struck 11 aces but only won 38 percent of the points when he missed his first serve.

Next up for Falla on Saturday at this grass-court tournament will be Germany's Philipp Kohlschreiber, who saved five match points before eking out a 6-4, 5-7, 7-6 (18-16) victory over countryman Dustin Brown.

Brown was eliminated a day after stunning Spanish world No. 1 Rafael Nadal 6-4, 6-1 in second-round action on Thursday.

Swiss world No. 4 Roger Federer, a six-time winner in Halle, advanced to the semifinals when Taiwan's Lu Yen-hsun was forced to pull out of the tournament due to injury.

His opponent on Saturday will be Japanese world No. 12 Kei Nishikori, who defeated American Steve Johnson 6-1, 7-6 (7-4).

The Gerry Weber Open is a key tune-up for Wimbledon, which gets underway on June 23.

Federer, who is aiming for a record eighth title at tennis' most prestigious event, suffered a disappointing second-round loss to Ukrainian Sergiy Stakhovsky at the All England Club last year. EFE