The former world number one went down 7-6 (7), 7-6 (4) to the 22-year-old Delbonis with the defeat coming just a month after Federer was knocked out of Wimbledon by Ukraine’s world number 116 Sergiy Stakhovsky in the second round.
Delbonis will play Fabio Fognini in Sunday’s final after the Italian 12th seed reached his second successive final by beating Spain’s Nicolas Almagro 6-4, 7-6 (1).
“I feel like I’m dreaming,” said Delbonis. “My key was to enjoy the match and enjoy playing this kind of player, because he’s the best of all time.” Saturday’s defeat will put the 31-year-old Federer under more pressure to justify that he can still be a major force in the sport.
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