Roger Federer of Switzerland reacts during his match against James Blake of the U.S. in the mens's singles tennis quarterfinals at the Beijing 2008 Olympic Games, August 14, 2008. [Agencies]

BEIJING -- Swiss world number one Roger Federer lost to American eighth seed James Blake in the men's singles quarterfinals of the Olympic tennis event on Thursday.

In a match delayed by rain for three hours, Federer was playing below standard, slumping at 6-4, 7-6(2) in just one hour and 30 minutes.

Federer had already looked shaky in the opening set, making more unforced errors and was totally outclassed by the American in baseline and serve.

Both players held serve in the first nine games of the opening set, but a long forehand from Federer gave Blake a break point with the Swiss serving at 4-5. Blake converted on it to draw the first blood after Federer drove the ball into the net.

In the second set, Federer had no signs of recovery, being broken in his first service game. Despite breaking back in Blake's next serve, Federer still handed the set and the whole match after losing the tie-break at 7-2.