Olympics Day 7 – Tennis

Juan Martin del Potro serves to Roger Federer. (Clive Brunskill/Getty Images)

Juan Martin del Potro serves to Roger Federer. (Clive Brunskill/Getty Images)

LONDON, ENGLAND – AUGUST 03: Juan Martin Del Potro of Argentina serves the ball to Roger Federer of Switzerland in the Semifinal of Men’s Singles Tennis on Day 7 of the London 2012 Olympic Games at Wimbledon on August 3, 2012 in London, England. (Photo by Clive Brunskill/Getty Images)