Sofia: Australia`s Samantha Stosur reached the WTA Tournament of Champions semi-finals on Friday with a 6-1, 6-4 win over Bulgarian wildcard Tsvetana Pironkova.
Stosur will face Russia`s Anastasia Pavlyuchenkova for a place in the final while Saturday`s other semi-final will feature former world number one Ana Ivanovic against in-form Romanian, Simona Halep who has five titles to her name this year.
"I definitely got a lot tighter as the match went on," Stosur said.
"I got off to a great start, then a tough service game trying to serve out the set. Thankfully I got through that, then it was a matter of holding serve from there. I got the break in the second set and managed to close it out, so I`m happy.
"It`s been great to be able to carry on from the last three or four weeks. To come here, the last event, to finish the group on top, hopefully I can continue the momentum in the semi-finals."
Ivanovic, the world number 16, made it to the last four despite losing her last group match 6-4, 3-6, 7-6 (7/1) to Russia`s Elena Vesnina.
Former French Open champion Ivanovic had led 5-2 in the final set.
The 22-year-old Halep made the semi-finals by winning all of her three group matches without conceding a set and dropping just 16 games.