2014 U.S. Open tennis tournament

Jelena Jankovic, of Serbia, returns a shot against Johanna Larsson, of Sweden, during the third round of the 2014 U.S. Open tennis tournament

Jelena Jankovic of Serbia, returns a shot against Johanna Larsson of Sweden

Maria Sharapova, of Russia, serves to Sabine Lisicki, of Germany, during the third round of the U.S. Open tennis tournament

Maria Sharapova of Russia serves to Sabine Lisicki of Germany

Petra Kvitova, of the Czech Republic, returns a shot to Aleksandra Krunic, of Serbia during the third round of the U.S. Open tennis tournament

Petra Kvitova of the Czech Republic returns a shot to Aleksandra Krunic of Serbia

Petra Kvitova of the Czech Republic steadies herself after an off-balance shot to Aleksandra Krunic of Serbia during the third round of the 2014 U.S. Open tennis tournament

Petra Kvitova of the Czech Republic steadies herself after an off-balance shot to Aleksandra Krunic of Serbia

Tommy Robredo of Spain lunges for but can't reach a shot by Nick Kyrgios of Australia in their third-round match at the U.S. Open tennis tournament

Tommy Robredo of Spain, lunges for but can't reach a shot by Nick Kyrgios of Australia

Eugenie Bouchard, of Canada, reacts after defeating Barbora Zahlavova Strycova, of the Czech Republic, during the third round of the 2014 U.S. Open tennis tournament

Eugenie Bouchard of Canada reacts after defeating Barbora Zahlavova Strycova of the Czech Republic

Serena Williams, of the United States, reacts to the crowd as she prepares to hit balls into the stands after defeating Varvara Lepchenko, of the United States, during the third round of the 2014 U.S. Open tennis tournament

Serena Williams of the United States reacts to the crowd 

Andy Murray, of the United Kingdom, signs autographs after defeating Andrey Kuznetsov, of Russia, during the third round of the 2014 U.S. Open tennis tournament