ISTANBUL, Oct. 27 (Xinhua) -- Victoria Azerenka, Petra Kvitova and Aginieszka Radwanska won on Thursday, the third day of the season-ending TEB BNP Paribas WTA Championships in Turkey's largest city Istanbul.

Azerenka became the first player to secure a semifinals spot after breezing past Li Na 6-2, 6-2 in the first match of the day.

In the second match of the day, Kvitova beat world No. 1 Caroline Wozniacki 6-4, 6-2 to leave the Dane's hopes of making the semifinals hanging by a thread.

In the final match of the day, Radwanska came from one set down to beat Vera Zvonareva 1-6, 6-2, 7-5 and kept her chances of qualifying for the semifinals alive.

The WTA's year-end finale, being held at Istanbul's Sinan Erdem Dome on indoor hard courts from Oct. 25-30, features the world's top eight singles players and top four doubles teams competing for the coveted title and a share of the 5 million U.S. dollars in prize money.

The round robin stage consists of two groups in the single's category with the top two from each group progressing to the semifinals.

The White group features Maria Sharapova (Russia), Victoria Azarenka (Belarus), Li Na (China) and Samantha Stosur (Australia) while the Red group features Caroline Wozniacki (Denmark), Petra Kvitova (Czech Republic), Vera Zvonareva (Russia) and Agnieszka Radwanska (Poland).

The competition will also feature the doubles pairs of Kveta Peschke/Katarina Srebotnik, Liezel Huber/Lisa Raymond, Gisela Dulko/Flavia Pennetta and Vania King/Yaroslava Shvedova.

France's Marion Bartoli and Germany's Andrea Petkovic are also in Istanbul as singles alternates.

Bartoli will make her appearance during the tournament Friday after Sharapova pulled out with injury after Wednesday's loss to Li Na.