Li Na made an encouraging start in her bid to qualify for her first WTA Championships semifinals when she contained a courageous second set battle by Sara Errani, the sixth-seeded Italian, to win 6-3, 7-6 (5) on Wednesday.

The first Chinese player to win a Grand Slam attacked with flair and ambition with her flat hitting and dominated many periods of the match, though she needed to fight and focus harder to regain control after her level dropped early in the second set.

"I have a very good physio," Li said after the match, explaining her enduringly good court coverage. And it seemed Errani, who had considered withdrawing with an injury, must have had good treatment too.

Errani appeared with spectacular blue taping from the back of her ankles up to both knees, but she was still able to run, fight and make it difficult for an opponent she had never beaten.

The wins means that if Li can oovercome former world No 1 Jelena Jankovic of Serbia on Thursday, she will almost certainly make the final four.

"It was important to win the first match because it is always tough. Sara was fighting a lot today, she is always a tough fighter," said Li.

Meanwhile, world No 1 Serena Williams beat Agnieszka Radwanska for the eighth time in eight matches to move towards the semifinals of the WTA Championships on Wednesday.

The American was again too strong for the Pole in a 6-2, 6-4 victory to stay in charge of Red Group with one more round-robin match to come against Petra Kvitova, another player to whom she has never lost.

"Radwanska definitely played pretty well. Am I happy? I guess. I'm happy to still be alive in the tournament. But, you know, I can always look to improve on some things," Williams said after her 75th match win of a dominant year.

"My serve wasn't as good today as it was yesterday, but, you know, you can't expect it to be great every day."

"It wasn't easy.' she said. "It's the end of the year and I'm a little tired, so I really had to fight in that second set to stay up mentally."

Earlier, in Li's White Group, Jankovic beat second seed Victoria Azarenka 6-4, 6-3, aided by 40 unforced errors from her erratic opponent.

"It feels incredible to beat Azarenka here in Istanbul," said former world No 1 Jankovic, making her first appearance at the event in three years.

"I was so excited to qualify and give myself a chance to play against the best players in the world once again, and to win today is amazing.

"Every match in the round-robin format counts, and every match is difficult too. I'm really happy. Beating Vika will give me a lot of confidence going into the next matches."

(China Daily 10/25/2013 page23)