Sofia - Simona Halep has battled back from a double break down in the third set to beat Ana Ivanovic 2-6, 6-1, 6-3 and reach the WTA Tournament of Champions final on Saturday.
Romanian top seed Halep will face Australian fourth seed Samantha Stosur who beat Anastasia Pavlyuchenkova, the sixth-seeded Russian, 6-1, 1-6, 6-3 in her semi-final.
On Sunday, Halep will be chasing her sixth title of 2013.
Ivanovic led 3-0 in the final set but Halep won 25 of the last 32 points to seal victory.
"I played really well when she had break points to make it 4-1, and I'm really happy with the way I came back in the end," Halep said.
"I'm a little bit injured in my leg but I'm very happy I was able to win. Now I'm going to rest and recover and I hope to just come back and enjoy the final."
Halep is now projected to rise from No.14 to No.11 on the new rankings.
Former US Open champion Stosur needed one hour and 45 minutes to see off Pavlyuchenkova.
Stosur relied on her powerful kick serves to take an early 3-0 lead in the first set against Pavlyuchenkova, who struggled with a very low first service percentage.
The 29-year-old Australian -- who is the oldest player in the tournament -- broke Pavlyuchenkova again in the sixth game to win the set.
The two traded breaks at the start of the second set but Stosur lost rhythm and concentration and made a number of unforced errors.
The Russian took advantage, breaking again in the fourth and sixth games and holding serve to take the set.
Stosur recovered in the decider and managed to break a tough Pavlyuchenkova in the fourth game.
The Russian saved a match point in the eighth game before the Australian finally took the set and the match with an ace.
"I didn't serve well today, but I still won the match," said Stosur.
"I started great, but in the second set everything turned upside down. In the third I gave it all to reach the final."
"Simona returns incredibly and I'm sure it will be very difficult match."
Results from the fifth day of the WTA Tournament of Champions on Saturday:
Simona Halep (ROM x1) bt Ana Ivanovic (SRB x2) 2-6, 6-1, 6-3
Samantha Stosur (AUS x4) bt Anastasia Pavlyuchenkova (RUS x6) 6-1, 1-6, 6-3