The 19-year-old American tennis player Sloane Stephens has provided the upset of the Australian Open by defeating her compatriot, the great Serena Williams, in a three-set thriller to reach the semi-finals in Melbourne.
Stephens beat the 31-year-old Williams 3-6 7-5 6-4, taking advantage of a back injury sustained by the Williams in the second set, and will now face the defending champion Victoria Azarenka of Belarus for a place in the finals.
The victory almost doubles the career prize money for Stephens - the teenager earns half a million Australian dollars for making the semi.
