Grounds crew dry Arthur Ashe Stadium after rain suspened action on Day Nine of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 4, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Elsa/Getty Images)
2012 US Open - Day 9
Victoria Azarenka of Belarus returns a shot against Samantha Stosur of Australia during their women's singles quarterfinals match on Day Nine of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 4, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Clive Brunskill/Getty Images)
2012 US Open - Day 10
Maria Sharapova of Russia reacts after defeating Marion Bartoli of France in their women's singles quarterfinal match on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)
2012 US Open - Day 10
Novak Djokovic of Serbia returns a shot during his men's singles fourth round match against Stanislas Wawrinka of Switzerland on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Clive Brunskill/Getty Images)
2012 US Open - Day 10
Andy Roddick of the United States reacts against Juan Martin Del Potro of Argentina during their men's singles fourth round match on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Elsa/Getty Images)
2012 US Open - Day 10
Andy Murray of Great Britain celebrates a point against Marin Cilic of Croatia during their men's singles quarterfinal match on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Clive Brunskill/Getty Images)
2012 US Open - Day 10
Serena Williams of the United States returns a shot during her women's singles quarterfinal match against Ana Ivanovic of Serbia on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)
2012 US Open - Day 10
Tomas Berdych of Czech Republic celebrates a set point during his men's singles quarterfinal match against Roger Federer of Switzerland on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)
2012 US Open - Day 1
Clouds roll in overhead as James Blake of the United States competes against Lukas Lacko of Slovakia during their men's singles first round match of the 2012 U.S. Open at the USTA Billie Jean King National Tennis Center on August 27, 2012 in the Flushing neighborhood, of the Queens borough of New York City. (Photo by Mike Stobe/Getty Images for USTA)
2012 US Open - Day 1
Petra Kvitova of Czech Republic returns a shot during her women's singles first round match against Polona Hercog of Slovenia on Day One of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 27, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)
2012 US Open - Day 1
Fireworks expload over Arthur Ashe Stadium during the national anthem in the opening ceremonies on Day One of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 27, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Michael Heiman/Getty Images)
2012 US Open - Day 3
Mikhail Youzhny of Russia reacts against Gilles Muller of Luxembourg during their men's singles first round match on Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)
2012 US Open - Day 3
Maria Sharapova of Russia returns a shot during her women's singles second round match against Lourdes Dominguez Lino of Spain on Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)
2012 US Open - Day 4
Ana Ivanovic of Serbia returns a shot against Sofia Arvidsson of Sweden during their women's singles second round match Day Four of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 30, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)
2012 US Open - Day 5
Laura Robson of Great Britain returns a shot against Na Li of China during their women's singles third round match on Day Five of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 31, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Elsa/Getty Images)
2012 US Open - Day 5
Victoria Azarenka of Belarus celebrates match point during her women's singles third round match against Jie Zheng of China on Day Five of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 31, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)
2012 US Open - Day 6
Serena Williams of the United States reacts against Ekaterina Makarova of Russian during their women's singles third round match on Day Six of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 1, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Elsa/Getty Images)
2012 US Open - Day 6
Roger Federer of Switzerland returns a shot against Fernando Verdasco of Spain during their men's singles third round match on Day Six of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 1, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Alex Trautwig/Getty Images)
2012 US Open - Day 6
Andy Murray of Great Britain reacts against Feliciano Lopez of Spain during their men's singles third round match on Day Six of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 1, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Dan Istitene/Getty Images)
2012 US Open - Day 6
Roger Federer of Switzerland looks on against Fernando Verdasco of Spain during their men's singles third round match on Day Six of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 1, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)
2012 US Open - Day 7
Novak Djokovic of Serbia reacts after winning his men's singles third round match against Julien Benneteau of France on Day Seven of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 2, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)
2012 US Open - Day 7
Maria Sharapova of Russia celebrates after defeating Nadia Petrova of Russia on Day Seven of the 2012 U.S. Open at the USTA Billie Jean King National Tennis Center on September 2, 2012 in the Flushing neighborhood, of the Queens borough of New York City. (Photo by Mike Stobe/Getty Images for USTA)
2012 US Open - Day 8
Serena Williams of the United States returns a shot against Andrea Hlavackova of Czech Republic during their women's singles fourth round match on Day Eight of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 3, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)
2012 US Open - Day 8
Angelique Kerber of Germany reacts against against Sara Errani of Italy during their women's singles fourth round match Day Eight of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 3, 2012 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)