SOFIA, Bulgaria -- Ana Ivanovic wasted a 5-2 lead in the third set to lose 6-4, 3-6, 7-6 (1) to Elena Vesnina in their last group match at the season-ending Tournament of Champions, but still advanced to the semifinals at the expense of her opponent.

Samantha Stosur and Anastasia Pavlyuchenkova also secured spots in the semis. They join Simona Halep, who has already qualified.

Vesnina's victory meant both she and Ivanovic finished round-robin play with 2-1 records, but Ivanovic advanced because of more sets won.

The sixth-seeded Pavlyuchenkova downed Alize Cornet of France, 6-2, 6-2, while Stosur defeated Bulgaria's Tsvetana Pironkova 6-1, 6-4.

In Saturday's semis, Ivanovic will play Halep, and Stosur will face Pavlyuchenkova.