Sofia - Ana Ivanovic overcame Sam Stosur 6-2, 5-7, 6-2 on Thursday for her second straight victory in the group stage at the season-ending WTA Tournament of Champions.
The two-time tournament winner played very aggressively to win the opening set in just 30 minutes. Stosur then broke Ivanovic's serve in the second set to go up 5-3. But Ivanovic got the early break at 2-0 in the third set and cruised from there. She will play Russia's Elena Vesnina on Friday with both players still trying to secure a spot in the semifinals.
Vesnina outlasted Bulgaria's Tsvetana Pironkova 6-2, 4-6, 6-0 for her first victory at the tournament.
In Thursday's last match, top-seeded Simona Halep of Romania swept past Ukraine's Elina Svitolina 6-1, 6-1, to finish the round-robin phase unbeaten. She had already qualified for Saturday's semi-finals.
Results from third day of WTA Tournament of Champions tournament in Sofia on Thursday (x denotes seeding):
Ana Ivanovic (SRB x2) bt Samantha Stosur (AUS x4) 6-2, 5-7, 6-2
Elena Vesnina (RUS x5) bt Tsvetana Pironkova (BUL x8) 6-2, 4-6, 6-0
Simona Halep (ROM x1) bt Elina Svitolina (UKR) 6-1, 6-1