Timea Bacsinszky of Switzerland celebrates after winning her match against Monica Niculescu of Romania at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Stefan Wermuth 

Andy Murray of Britain celebrates after winning the first set of his match against Ivo Karlovic of Croatia at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Toby Melville 

Lucie Safarova of the Czech Republic reacts to breaking serve during her match against Coco Vandeweghe of the U.S.A. at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Stefan Wermuth 

Dustin Brown of Germany celebrates after winning his match against Rafael Nadal of Spain at the Wimbledon Tennis Championships in London, July 2, 2015. REUTERS/Stefan Wermuth 

Novak Djokovic of Serbia celebrates after winning his match against Jarkko Nieminen of Finland at the Wimbledon Tennis Championships in London, July 1, 2015. REUTERS/Toby Melville 

Jelena Jankovic of Serbia celebrates after winning her match against Petra Kvitova of the Czech Republic at the Wimbledon Tennis Championships in London, July 4, 2015. REUTERS/Henry Browne 

Caroline Wozniacki of Denmark celebrates after winning her match against Denisa Allertova of the Czech Republic at the Wimbledon Tennis Championships in London, July 2, 2015. REUTERS/Toby Melville 

Sabine Lisicki of Germany celebrates after winning the second set of her match against Christina McHale of the U.S.A. at the Wimbledon Tennis Championships in London, July 2, 2015. REUTERS/Stefan Wermuth 

Serena Williams of the U.S.A. celebrates winning a game during her match against Heather Watson of Britain at the Wimbledon Tennis Championships in London, July 3, 2015. REUTERS/Suzanne Plunkett 

Maria Sharapova of Russia celebrates after winning her match against Zarina Diyas of Kazakhstan at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Suzanne Plunkett 

Ricardas Berankis of Lithuania celebrates after winning the fourth set of his match against Marin Cilic of Croatia at the Wimbledon Tennis Championships in London, July 1, 2015. REUTERS/Toby Melville 

Vasek Pospisil of Canada celebrates after winning his match against James Ward of Britain at the Wimbledon Tennis Championships in London, July 4, 2015. REUTERS/Stefan Wermuth 

Rafael Nadal of Spain celebrates after winning his match against Thomaz Bellucci of Brazil at the Wimbledon Tennis Championships in London, June 30, 2015. REUTERS/Stefan Wermuth