Here's a short story:

(CNN) -- Maria Sharapova has pulled out of the season-ending WTA Championships in Istanbul after suffering successive straight-sets defeats. 

The Russian lost to China's Li Na 7-6 (7-4) 6-4, who had herself not won a match, or even a set, since August. 

It was a match that ebbed and flowed as Li came from 2-4 down in the first set to force a tie-break, which she won despite losing the first four points. 

Li, who this year became the first Asian Grand Slam winner after victory in the French Open, then fought off a late Sharapova surge when 5-2 up to take the second set 6-4. The defeat followed Sharapova's capitulation against U.S. Open champion Sam Stosur 6-1, 7-5 on Wednesday. 

"I really wasn't thinking about too much during the match," Li was quoted as saying on the WTA's official website after the match. 

"I'm so happy I was able to beat Maria because she's a top player, and also today was my first match ever at the Championships, so I want to thank all the crowd here for supporting me." 

But for Sharapova, who has struggled with an ankle injury but had the chance to become world number one with victory in Istanbul, there were some positives to be taken from two defeats in two days. 

"I just have to be pleased that I recovered quickly enough to allow myself a chance of playing here," she told AFP. 

World number one Caroline Wozniacki crashed to defeat in her second red group match, losing 6-2 4-6 6-3 to Russia's Vera Zvonareva.  (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: Where is Sharapova from?
Guess: Russia

Question: What Championship was she in?
Guess: WTA Championships

Question: Did she quit?
Guess: Yes

Question: What kind of defeat made her quit?
Guess: lost to China's Li Na

Question: How many wins did Li Na have?
Guess: 7-6 (7-4) 6-4

Question: When was the last time she won?
Guess: August

Question: Who was the U.S. Open winner?
Guess: Sam Stosur

Question: When did Sharapova play them?
Guess: Wednesday

Question: What is Li the first of?
Guess: first Asian Grand Slam winner

Question: What kind of injury did Sharapova have?
Guess: ankle injury

Question: How many times did she lose in two day?
Guess: Two

Question: Where were they playing?
Guess: Istanbul

Question: What is Caroline Wozniacki ranked?
Guess: World number one

Question: Who beat her?
Guess: Vera Zvonareva

Question: In which match?
Guess: red group match

Question: Was it her first?
Guess: No

Now answer the following question in the same format.

Question: Which one was it?

second