Serena Williams readies her forehand at the 2013 China Open.
The China Open is the last major tournament before the WTA Championships.
It's a chance for the top stars to punctuate their 2013 season. Serena Williams can put an exclamation mark on her No. 1 ranking. Caroline Wozniacki would like to erase the many question marks surrounding her career.
As the tournament winds down this weekend, here's a look at what's at stake for the top stars.
Li Na prepares to serve at the China Open.
It would also delight the Chinese fans who've turned out to see her.
Victoria Azarenka in her loss at China Open.
Last week, Azarenka told Sports Illustrated that Serena Williams is one of greatest ever, but that she's closing the gap.
Yes, her matches against Williams have become more competitive. But Azarenka has lost ground in the rankings.
Sloane Stephens autographs a tennis ball at China Open.
Sloane Stephens is ranked No. 13. With a good finish at the China Open she positions herself to make a serious run at the Top 10.
Going into this tournament, fewer than 600 points separated Stephens from the 10th-ranked player, Marion Bartoli. Unless she sneaks into the year-end championships, this is Stephens' last chance to pick up hefty points.
Petra Kvitova prepares to hit a backhand at the China Open.
After Petra Kvitova upset Sharapova at Wimbledon in 2011, people thought the hard-hitting Czech might become a fixture in Grand Slam finals.
It hasn't happened. Instead, Kvitova has been inconsistent. Lately, she's been playing better. She won the Pan Pacific Open and got herself back in the hunt for a spot in the WTA Championships.
Kvitova needs to do well here to become a factor and not an afterthought in the conversation about the elite players.
Sara Errani hits a forehand at the China Open.
Sara Errani, the little engine that could, has been the victim of her own success. Her surprise appearance in last year's French Open final propelled her into the Top 10.
She's spent much of the year ranked No. 5. Never mentioned as a serious contender to win it all, Errani needed to survive longer in this tournament. However, Errani lost to Kvitova, one of those tall, big-hitting women expected to win it all.
Caroline Wozniacki at the China Open.
Remember when the worst thing someone could say about Wozniacki was that she's one of the best players to never have won a Grand Slam?
Now, Wozniacki is fighting to become relevant again. She's ranked No. 8 and eager to return to the top. Reaching the finals here or knocking off a player in the Top Five, would go a long way to making her relevant again.
Agnieszka Radwanska at China Open.
Up 2-0 in the third set against Serena Williams in the 2012 Wimbledon final, Radwanska was four games away from becoming the first Polish woman to ever hold the No. 1 ranking.
Now ranked No. 4, Radwanska is facing a serious challenge from Li Na. Less than 500 points apart, their performances at the China Open and the year-end championships will determine who finishes ahead.
Serena Williams at China Open
Williams has already locked up the No. 1 ranking for the year. So what's left to gain?
Williams can put a stranglehold on the No. 1 ranking so tight that it carries her all the way into next spring.
After Azarenka won the Aussie Open it appeared the fight for No. 1 would come down to the wire. Only a few hundred points separated the three women at the top. But now Williams has nearly a 3,000-point lead over Azarenka. More than 4,000 points separate her and Sharapova. The other players aren't even in the same hemisphere.
Winning in China would put Williams in her own galaxy.