Result: Caroline Wozniacki defeated in Istanbul

World number one Caroline Wozniacki was unable to build upon her victory over Agnieszka Radwanska as she slipped to a three-set defeat to Vera Zvonareva in Istanbul this evening.

Zvonareva, 27, took the first set 6-2 with relative ease, but Wozniacki hit back in the second to draw the match level with a 6-4 success.

However, Zvonareva regained her composure in the deciding set by breaking the Dane twice before recording a 6-4 4-6 6-3 victory.

The Russian's victory follows her straight-sets defeat to Petra Kvitova yesterday afternoon.