Angelique Kerber of Germany reacts after her tennis match against Serena Williams of the USA at the WTA championship in Istanbul, Turkey, Tuesday, Oct. 23, 2012. (AP Photo)

 

              Angelique Kerber of Germany reacts after her tennis match against Serena Williams of the USA at the WTA championship in Istanbul, Turkey, Tuesday, Oct. 23, 2012. (AP Photo)
Angelique Kerber of Germany reacts after her tennis match against Serena Williams of the USA at the WTA championship in Istanbul, Turkey, Tuesday, Oct. 23, 2012. (AP Photo)
Tags: Germany , USA