Serena Williams of the US hits a return to Japan's Ayumi Morita during their third round match at the Australian Open tennis championship in Melbourne, Australia, Saturday, Jan. 19, 2013. (AP Photo/Andy Wong)

Associated Press
Serena Williams of the US hits a return to Japan's Ayumi Morita during their third round match at the Australian Open tennis championship in Melbourne, Australia, Saturday, Jan. 19, 2013. (AP Photo/Andy Wong)
Serena Williams of the US hits a return to Japan's Ayumi Morita during their third round match at the Australian Open tennis championship in Melbourne, Australia, Saturday, Jan. 19, 2013. (AP Photo/Andy Wong)