Denis Istomin of Uzbekistan reacts during his men's singles fourth-round match against Andy Murray of Great Britain. (Photo by Clive Brunskill/Getty Images)
2013 US Open - Day 9
British tennis player Andy Murray reacts to winning against Uzbekistan's Denis Istomin during their 2013 US Open men's singles match. (Photo credit should read EMMANUEL DUNAND/AFP/Getty Images)
2013 US Open - Day 9
Stanislas Wawrinka of Switzerland plays a backhand during his men's singles fourth-round match against Tomas Berdych of Czech Republic. (Photo by Matthew Stockman/Getty Images)
2013 US Open - Day 9
Tomas Berdych of Czech Republic serves during his men's singles fourth-round match against Stanislas Wawrinka of Switzerland. (Photo by Elsa/Getty Images)
2013 US Open - Day 9
Denis Istomin of Uzbekistan returns a forehand during his men's singles fourth-round match against Andy Murray of Great Britain. (Photo by Clive Brunskill/Getty Images)
2013 US Open - Day 9
Serena Williams of United States of America plays a forehand during her women's singles quarterfinal match against Carla Suarez Navarro of Spain. (Photo by Clive Brunskill/Getty Images)
2013 US Open - Day 9
David Schwimmer watches the women's singles quarterfinal match between Serena Williams of United States of America and Carla Suarez Navarro of Spain. (Photo by Matthew Stockman/Getty Images)
2013 US Open - Day 9
Leonardo DiCaprio and Lukas Haas watch the women's singles quarterfinal match between Serena Williams of United States of America and Carla Suarez Navarro of Spain. (Photo by Matthew Stockman/Getty Images)
2013 US Open - Day 9
A general view of a women's singles quarterfinal match between Serena Williams of the United States and Carla Suarez Navarro of Spain. (Photo by Mike Stobe/Getty Images for the USTA)
2013 US Open - Day 9
Novak Djokovic of Serbia celebrates match point during his men's singles fourth-round match against Marcel Granollers of Spain. (Photo by Mike Stobe/Getty Images for the USTA)
2013 US Open - Day 9
Lleyton Hewitt of Australia plays a forehand during his men's singles fourth-round match against Mikhail Youzhny of Russia. (Photo by Clive Brunskill/Getty Images)
2013 US Open - Day 9
Mikhail Youzhny of Russia celebrates a point during his men's singles fourth-round match against Lleyton Hewitt of Australia. (Photo by Clive Brunskill/Getty Images)
2013 US Open - Day 9
Novak Djokovic of Serbia returns a shot to Marcel Granollers of Spain during a 2013 US Open men's fourth-round singles match. (Photo credit should read STAN HONDA/AFP/Getty Images)
2013 US Open - Day 9
Novak Djokovic of Serbia returns a shot to Marcel Granollers of Spain during a 2013 US Open men's fourth-round singles match at the USTA Billie Jean King National Tennis Center. (Photo credit should read STAN HONDA/AFP/Getty Images)
2013 US Open - Day 9
Li Na (L) of China shakes hands with Ekaterina Makarova of Russia after Li won, 6-4, 6-7 (5), 6-2 in the 2013 US Open women's singles quarterfinals. (Photo credit should read STAN HONDA/AFP/Getty Images)
