BEIJING — Roger Federer's bid for his first Olympic singles medal has ended with a loss to American James Blake.

With the sort of lackluster performance that was once unthinkable for Federer, he was eliminated in the quarterfinals on Thursday night.

The upset was a stunner in that Blake had won only a single set in their previous eight matches. But the top-seeded Federer is battling a yearlong slump that has left him stalled at 12 major titles, two shy of Pete Sampras' record.

Federer's latest defeat means no rematch in Sunday's final against Nadal, who won in epic fashion when they met for the Wimbledon title.