U.S. Open 2013 (96 images)

Agnieszka Radwanska of Poland reacts after losing a game to Maria-Teresa Torro-Flor of Spain during round-two action at the U.S. Open Championship held at the USTA Billie Jean King National Tennis Center on August 28, 2013 in New York City. Radwanska won 6-0, 7-5. UPI Photo/Monika Graff

Dinah Pfizenmaier of Germany (L) and Victoria Azarenka of Belarus shake hands at the conclusion of their round-one match where Pfizenmaier lost in two sets at the U.S. Open Championship held at the USTA Billie Jean King National Tennis Center on August 27, 2013 in New York City. Azarenka won 6-0, 6-0. UPI Photo/Monika Graff

Victoria Azarenka of Belarus reacts after losing a point to Dinah Pfizenmaier of Germany in the first set of round-one play at the U.S. Open Championship held at the USTA Billie Jean King National Tennis Center on August 27, 2013 in New York City. UPI Photo/Monika Graff

Novak Djokovic of Serbia returns the ball to Ricardas Berankis of Lithuania in the first set of round one action at the U.S. Open Championship held at the USTA Billie Jean King National Tennis Center on August 27, 2013 in New York City. Djokovic won 6-1,6-2, 6-2. UPI Photo/Monika Graff