Agnieszka Radwanska has won her opening match of this year's WTA Finals thanks to a convincing straight-sets victory over Wimbledon champion Petra Kvitova.

There was little to separate the players at the start of the opening set, but Radwanska broke twice late on to take it 6-2 with just 41 minutes played.

World number three Kvitova then fought back in the second as a break of serve allowed her to go 3-2 ahead against the Pole.

However, Radwanska quickly regained the advantage, breaking twice more to close out the contest 6-2 6-3.

Tuesday's other match in the White Group saw Caroline Wozniacki earn a thrilling three-set win over Maria Sharapova.