Tennis-WTA

Wins for Williams, Sharapova & Radwanska

There were victories for Agnieszka Radwanska, Serena Williams and Maria Sharapova in their opening matches as the WTA Championships started in Istanbul.

Radwanska defected defending champion Petra Kvitova 6-3 6-2 while American Williams beat Germany's Angelique Kerber 6-4 6-1.

Russia's Maria Sharapova recorded a 6-3 6-2 victory over Italy's Sara Errani in a repeat of the French Open final.

Victoria Azarenka and Li Na are the other players in the round-robin event.

The top eight women in the world are taking part in the end-of-season showpiece event.
Belarusian Azarenka, Williams, Kerber and China's Na are in the Red Group, with the remaining players making up the White Group.

Two from each group go through to the semi-finals

Williams and Sharapova are favourite to win the event.

Williams has played a curtailed schedule because of injuries and illness but she holds a 10-1 career record against Azarenka.  The American is ranked No 3 in the world, but she holds a 9-1 record this year against the other seven finalists in Istanbul