Sofia, Bulgaria, 2 November 2013 | AFP/

Australia’s Sam Stosur has reached the WTA Tournament of Champions semifinals with a 6-1 6-4 win over Bulgarian wildcard Tsvetana Pironkova on Friday in Sofia.

Fourth-seeded Stosur will face Russia’s Anastasia Pavlyuchenkova for a place in the final, while Saturday’s other semifinal will feature former world No.1 Ana Ivanovic against in-form Romanian Simona Halep, who has five titles to her name this year.

Pavlyuchenkova, seeded sixth, accounted for French No.7 seed Alize Cornet 6-2 6-2.

Stosur’s victory helped her top her group after the completion of the round-robin stage of the event.

“It’s great to be able to carry on from the last three or four weeks (Stosur won in Osaka and finished runner-up in Moscow), and then come here in the last event, play the round-robin group and come out on top which is a good feeling,” she said.

“Hopefully tomorrow I can keep building and playing even better as the week continues.”

She looked in fine form against the 119th-ranked Pironkova, dominating the first set and knuckling down in the second when proceedings got a little tighter.

Five aces and a winning percentage of 86 on first serve points were keys to the victory, which came in just one hour and 12 minutes.

“Definitely got a lot tighter as the match went on. I got off to a pretty good start at 5-0 up … I was getting opportunities but not being able to take them at the start of that second set,” Stosur reflected.

“I think when I serve well and serve with a high percentage I generally win a lot of points with it so that always helps my game and it all follows through together.

“It’s been good so far but hopefully I can pick it up because surely expecting a tougher match in the semis.”

Ivanovic, the world No.16 and second seed, finished second behind Stosur in their group and made it to the last four despite losing her last group match 6-4 3-6 7-6(1) to Russia’s No.5 seed Elena Vesnina.

Ivanovic, a French Open winner, had led 5-2 in the final set.

The 22-year-old Halep made the semifinals by winning all three group matches without conceding a set and dropping just 16 games.