Venus Williams, left, and Serena Williams wave as they walk off the court following their 6-1, 6-4 loss to Russia's Maria Kirilenko and Nadia Petrova. -Photo by AP

Andy Murray of Great Britain celebrates a point in his men's singles fourth round match against Milos Raonic of Canada. -Photo by AFP

Mike Bryan (R) and Bob Bryan of the United States celebrate during their men's doubles third round match against Santiago Gonzalez of Mexico and Scott Lipsky of the United States. -Photo by AFP

New York Mayor Michael Bloomberg watches Andy Murray of Great Britain play Milos Raonic of Canada. -Photo by AFP

Taylor Townsend of the United States serves next to her partner Gabrielle Andrews of the United States during their girls' doubles first round match against Ellen Allgurin of Sweden and Rebecca Peterson of Sweden. -Photo by AFP

Agnieszka Radwanska of Poland reacts to a point against Roberta Vinci of Italy. -Photo by AFP

Australia's Lleyton Hewitt returns a shot to Spain's David Ferrer. -Photo by AP