Defending champion Petra Kvitova, Angelique Kerber and Sara Errani are the latest players to qualify for the WTA Championships, leaving only one spot up for grabs in the exclusive eight-woman tournament.
Victoria Azarenka, Maria Sharapova, Agnieszka Radwanska and Serena Williams previously earned their way to Istanbul, where every Grand Slam champion and runner-up this year is scheduled to be in the field for the season finale on Oct. 23-28.
Li Na can secure the eighth and final spot on Friday by defeating Radwanska in the quarterfinals of the China Open or if Marion Bartoli, who is also in the quarterfinals, loses to Carla Suarez Navarro. Bartoli would need to win Beijing and the Moscow title next week to overtake Li.
The fifth-ranked Kvitova hasn't had the type of season many expected after a 2011 in which she won six titles (including Wimbledon), rose from No. 34 to No. 2 and was named Player of the Year. But even though "disappointing" and "Kvitova" have been used in the same sentence all through 2012, she still made the semifinals of the Australian Open and the French Open (where she fell to Sharapova both times) and the quarterfinals of Wimbledon, where she lost to Williams in the best match of power tennis in 2012. The 22-year-old Kvitova, who dealt with injury and illness early in the season, also won titles in Montreal and New Haven.
Kerber came out of nowhere to make the U.S. Open semifinals last year and carried that confidence into 2012, cracking the top 10 for the first time, reaching the Wimbledon semifinals, winning her first two career titles and taking a tour-leading 60 victories into her quarterfinal match against Sharapova in Beijing. The 24-year-old German is up to sixth in the rankings.
The pint-sized Errani's breakthrough performance rivals Kerber's. Errani, 25, spent years in the shadows of fellow Italians Flavia Pennetta and Francesca Schiavone, relegated to little more than a doubles specialist. But a racket change in January and noticeable improvement in her fitness have changed everything. After beginning the year ranked 45th, Errani has climbed to a career-high No. 7 by winning won four titles (she entered 2012 with two) and advancing to the French Open final and U.S. Open semifinals. That's on top of a stellar year in doubles with Roberta Vinci, as they've combined for eight titles, including the French Open and U.S. Open, to grab the No. 1 ranking.