The Australian Open

7a8f75bc41b70c02490f6a70670018d9.jpg

Caroline Wozniacki of Denmark hits a backhand return to Christina McHale of the U.S. during their second round match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 16, 2014.(AP Photo/Eugene Hoshiko)

e22278cd41b70c02490f6a7067005dae.jpg

Caroline Wozniacki of Denmark hits a forehand return to Christina McHale of the U.S. during their second round match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 16, 2014.(AP Photo/Aaron Favila)

08ee93d741690a02490f6a706700ee6e.jpg

Maria Sharapova of Russia reacts during her second round match against Karin Knapp of Italy at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 16, 2014.(AP Photo/Aaron Favila)