Olympics: The thrill and the agony

Japan's Kei Nishikori reacts after losing a point against Argentina's Juan Martin del Potro during their men's single tennis quarterfinal match at the London 2012 Olympic Games in London on August 2, 2012. Del Potro defeated Nishikori, 6-4, 7-6, to advance to the semifinals.

Credit: MARTIN BERNETTI/AFP/Getty Images