By Magdalena
Stanislav
 |
| Agnieszka Radwanska stuns defending champion Petra Kvitova at WTA Championships 2012 |
ISTANBUL, Turkey
(TheSportsNEXT) October 24, 2012: Maria Sharapova of Russia, Agnieszka Radwanska,
and Serena Williams of United States won their first matches at the year-ending
WTA Championships in Istanbul on Tuesday.
