Serena Williams of the United States waves to the crowd after defeating Vesna Dolonc of Serbia in their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Serena Williams of the United States reacts after losing a point to Vesna Dolonc of Serbia during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Serena Williams of the United States serves to Vesna Dolonc of Serbia during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Serena Williams of the United States makes a forehand return to Vesna Dolonc of Serbia during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Serena Williams of the United States makes a forehand return to Vesna Dolonc of Serbia during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2014.(AP Photo/Aaron Favila)
Serena Williams of the United States celebrates after defeating Ashleigh Barty of Australia in their first round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 13, 2014.(AP Photo/Aaron Favila)