Argentina's Juan Martin del Potro returns the ball during his men's singles semifinal round match against Switzerland's Roger Federer of the 2012 London Olympic Games at the All England Tennis Club in... more 

Argentina's Juan Martin del Potro returns the ball during his men's singles semifinal round match against Switzerland's Roger Federer of the 2012 London Olympic Games at the All England Tennis Club in Wimbledon, southwest London. Federer won 3-6, 7-6 (7/5), 19-17 less