Sabine Lisicki of Germany serves during her women's singles third-round match against Ekaterina Makarova of Russia on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
John Oliver (left) and Wyatt Cenac of "The Daily Show" attend the US Open at USTA Billie Jean King National Tennis Center on Augg. 30, 2013 in Flushing. (credit: Getty Images)
2013 US Open - Day 5
Tomas Berdych of the Czech Republic celebrates his victory in his men's singles second-round match over Denis Kudla of the United States on Day 5 of the 2013 US Open at the USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)(
US Open Day 5
Jelena Jankovic of Serbia complains to an umpire after a shot against Kurumi Nara of Japan during their 2013 US Open women's singles match at the USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Kurumi Nara of Japan returns a shot to Jelena Jankovic of Serbia during their 2013 US Open women's singles match at the USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Manhattan. (credit: Getty Images)
US Open Day 5
Andy Murray of Great Britain serves during his men's singles second-round match against Leonardo Mayer of Argentina on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
A general view of Louis Armstrong Stadium as Andy Murray of Great Britain serves during his men's singles second-round match against Leonardo Mayer of Argentina on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Sloane Stephens of the United States serves during her women's singles third-round match against Jamie Hampton of the United States on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Novak Djokovic of Serbia signs autographs for fans after winning his men's singles second-round match against Benjamin Becker of Germany on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Angelique Kerber of Germany plays a backhand during her women's singles third-round match against Kaia Kanepi of Estonia on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Martina Hingis of Switzerland in action next to her partner, Daniela Hantuchova of Slovakia (not pictured), during their women's doubles first-round match against Sara Errani and Roberta Vinci of Italy on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
2013 US Open - Day 5
Ekaterina Makarova of Russia plays a backhand during her women's singles third-round match against Sabine Lisicki of Germany on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Lleyton Hewitt of Australia plays a backhand during his men's singles second-round match against Juan Martin Del Potro of Argentina on Day 5 of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Andy Murray of Great Britain celebrates victory during his men's singles second-round match against Leonardo Mayer of Argentina on Day Five of the 2013 US Open at USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)
US Open Day 5
Ivo Karlovic of Croatia returns a shot to Stanislas Wawrinka of Switzerland during their 2013 US Open men's singles match at the USTA Billie Jean King National Tennis Center on Aug. 30, 2013 in Flushing. (credit: Getty Images)