Novak Djokovic takes on Mikhail Youzhny in quarterfinals match at the U.S. Open in New York

Novak Djokovic of Serbia returns the ball to Mikhail Youzhny of Russia during the second set of their quarterfinals match at the U.S. Open Championship held at the USTA Billie Jean King National Tennis Center on September 5, 2013 in New York City. UPI Photo/Monika Graff