HAMBURG, Germany — Roger Federer lost to Argentine qualifier Federico Delbonis 7-6 (7), 7-6 (4) Saturday in the semifinals of the German Tennis Championships.
Federer, a four-time champion in Hamburg, was outplayed by the 114th-ranked left-hander who advanced to his first career final.
"He played well, he was a little more aggressive," Federer said.
Federer took a wild card for Hamburg after losing in the second round at Wimbledon.
In the final, Delbonis will play Fabio Fognini of Italy. Fognini defeated third-seeded Nicolas Almagro of Spain 6-4, 7-6 (1).
Federer has dropped to No. 5, his lowest ranking in a decade. The 31-year-old Swiss ace's only title this year came on grass before Wimbleon in Halle, Germany.
The defending Wimbledon champion, Federer lost to No. 116 Sergiy Stakhovsky — a player who failed to qualify for Hamburg. It was his earliest Grand Slam defeat in 10 years, and his first loss to a player ranked outside the top 100 since 2005.
Federer changed his racket after Wimbledon, going for a bigger frame. But he struggled in Hamburg, going to three sets in two of his previous three matches.