Fifth seed Ana Ivanovic was unable to capitalise on her lead over top seed Vera Zvonareva and book her place in the final of the Mercury Insurance Open.
Ivanovic took the opening set 7-5 but Zvonareva battled back to take a 5-7 6-4 6-4 victory.
The Russian will now face third seed Agnieszka Radwanska in the final.
The Pole also came from behind to beat German second seed Andrea Petkovic 4-6 6-0 6-4.
Ivanovic took the opening set 7-5 but Zvonareva battled back to take a 5-7 6-4 6-4 victory.
The Russian will now face third seed Agnieszka Radwanska in the final.
The Pole also came from behind to beat German second seed Andrea Petkovic 4-6 6-0 6-4.