World No 5 Li Na has become the latest player to book her place in the season-ending WTA Championships in Istanbul.
Just three places remain up for grabs after the Chinese star became the fifth woman to qualify for the prestigious, season-ending event.
The top eight singles players and top four doubles teams will all take part in the $6 million tournament from October 22-27.
"I'm so happy to have qualified again," Li told the official WTA website.
"I had a great time in Istanbul last year and I'm looking forward to coming back and playing my best tennis for the fans in Turkey."
The former French Open champion joins the world's top four players - Serena Williams, Victoria Azarenka, Maria Sharapova and Agnieszka Radwanska - in the field.
The final three qualification slots are currently occupiued by Sara Errani, Petra Kvitova and Jelena Jankovic, but Roberta Vinci and Sloane Stephens remain very much in the hunt, especially given Sharapova is a doubt due to injury.