Britain's Andy Murray reacts during his semifinal match against Switzerland's Roger Federer at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 25, 2013. (AP Photo/Dita Alangkara)
Victoria Azarenka of Belarus waves to the crowd after winning her semifinal match against Sloane Stephens of the US at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 24, 2013. (AP Photo/Andrew Brownbill)
On Wednesday at the Australian Open, 19-year-old Sloane Stephens defeated her hero Serena Williams, 3-6, 7-5, 6-4 to advance to the semifinals in Melbourne, Australia. (Associated Press)
Serbia's Novak Djokovic celebrates his win over Tomas Berdych of the Czech Republic in their quarterfinal match at the Australian Open tennis championship in Melbourne, Australia, Tuesday, Jan. 22, 2013. (AP Photo/Dita Alangkara)
Li Na celebrates after defeating Agnieszka Radwanska in their quarterfinal match at the Australian Open in Melbourne, Australia on Jan. 22, 2013. (Associated Press)
Russia's Maria Kirilenko hits a return to Serena Williams of the US during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 21, 2013. (AP Photo/Dita Alangkara)
Serbia's Novak Djokovic, right, embraces Switzerland's Stanislas Wawrinka after winning their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 21, 2013.(AP Photo/Andy Wong)
Serbia's Novak Djokovic celebrates after defeating Switzerland's Stanislas Wawrinka in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 21, 2013. (AP Photo/Mark Baker)
Serbia's Novak Djokovic reacts during his fourth round match against Switzerland's Stanislas Wawrinka at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 20, 2013.(AP Photo/Dita Alangkara)
Russia's Ekaterina Makarova celebrates after defeating Germany's Angelique Kerber in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 20, 2013. (AP Photo/Dita Alangkara)
Switzerland's Roger Federer reacts during his third round match against Australia's Bernard Tomic at the Australian Open tennis championship in Melbourne, Australia, Saturday, Jan. 19, 2013. (AP Photo/Andy Wong)