Defending champion Ivanovic reaches final at Bali

Ana Ivanovic will defend her title against Spain's Anabel Medina Garrigues in the final of the Commonwealth Bank Tournament of Champions after eliminating Nadia Petrova on Saturday.

The Serbian former world number one, who will play the final on her 24th birthday on Sunday, thrashed Russia's Petrova 6-1 in the first set, with a powerful serve and winning forehands from the baseline.

Petrova made a solid comeback in the second set and came neck-and-neck with Ivanovic with five games all and a tie-breaker looming.

Losing her early dominance, Ivanovic was thrown to the ground several times trying to reach Petrova's smashes to the corners of the court.

Ivanovic however found enough winners in her game to avoid a tie-breaker, stealing Petrova's last serve to finish the match 6-1, 7-5.

"I played really well from the beginning," Ivanovic said.

"Then that game (in the second set) at 2-0, she really raised her game and went for more shots and made less errors and was serving bigger," she said.

Medina Garrigues won her semi-final match against Sabine Lisicki of Germany, who retired with a back injury with the score at 6-3, 4-6, 4-0.

Medina Garrigues won the first-round quarter-finals Thursday when her opponent Marion Bartoli pulled out with an ankle injury, having made match point several times.

Ivanovic is pegged as the favourite against Medina Garrigues.