NEW YORK, NY - SEPTEMBER 01: Jelena Jankovic of Serbia returns a shot against Agnieszka Radwanska of Poland 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 Alex Trautwig/Getty Images)
2012 US Open - Day 6
NEW YORK, NY - SEPTEMBER 01: Jelena Jankovic of Serbia returns a shot against Agnieszka Radwanska of Poland 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
Kei Nishikori of Japan returns the ball to Marin Cilic of Croatia during their men's singles match at the 2012 US Open tennis tournament on September 1, 2012 in New York. (DON EMMERT/AFP/GettyImages)
2012 US Open - Day 6
Marin Cilic of Croatia returns the ball to Kei Nishikori of Japan during their men's singles match at the 2012 US Open tennis tournament on September 1, 2012 in New York. (DON EMMERT/AFP/GettyImages)
2012 US Open - Day 6
GEW YORK, NY - SEPTEMBER 01: Serena Williams of the United States returns a shot 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 Al Bello/Getty Images)
2012 US Open - Day 6
NEW YORK, NY - SEPTEMBER 01: Jack Sock of the United States returns the ball against Nicolas Almagro 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 Cameron Spencer/Getty Images)
2012 US Open - Day 6
The USTA Billie Jean King National Tennis Center in New York on September 1, 2012. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 6
Ekaterina Makarova of Russia plays against Serena Williams of the US (4) during their 2012 US Open women's singles match at the USTA Billie Jean King National Tennis Center in New York on September 1, 2012. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 6
Serena Williams of the US (4) celebrates after winning against Ekaterina Makarova of Russia during their 2012 US Open women's singles match at the USTA Billie Jean King National Tennis Center in New York on September 1, 2012. Williams won 6-4, 6-0. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 6
NEW YORK, NY - SEPTEMBER 01: Ekaterina Makarova of Russian returns a shot against Serena Williams of the United States 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
NEW YORK, NY - SEPTEMBER 01: Andy Murray of Great Britain returns a shot 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 Matthew Stockman/Getty Images)
2012 US Open - Day 6
NEW YORK, NY - SEPTEMBER 01: Jack Sock of the United States serves the ball against Nicolas Almagro 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 Cameron Spencer/Getty Images)
2012 US Open - Day 6
NEW YORK, NY - SEPTEMBER 01: Serena Williams of the United States looks on against Ekaterina Makarova of Russia 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 Al Bello/Getty Images)
2012 US Open - Day 6
Serena Williams of the US (4) plays against Ekaterina Makarova of Russia during their 2012 US Open women's singles match at the USTA Billie Jean King National Tennis Center in New York on September 1, 2012. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 6
NEW YORK, NY - SEPTEMBER 01: Andy Murray of Great Britain reacts after a serve 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 Michael Heiman/Getty Images)
