Serena Williams Retains the WTA Title in Istanbul.

Serena Williams fought back from one set down to beat China’s Li Na and retain her WTA Championship title in Istanbul.

Li, who became the highest ever (third) ranked Asian following her semi-final victory over Petra Kvitova, lost the final to a fired up Williams 2-6, 6-3, 6-0 to claim her fourth WTA title.

Serena becomes the first player to defend the title since Justine Henin in 2007. She will finish year 2013 as number one ranked player for the third time in her career (2002 and 2009) after winning 78 of her 82 matches.

Serena Williams Lifts the Billie Jean King Trophy.
Serena Williams Lifts the Billie Jean King Trophy.

After Sunday’s victory, the American said: “It was an awesome year of tennis. To end with the Billie Jean King trophy after 40 years and after everything we had the celebration for this year, I don’t know if it’s written or what, but it’s just really exciting.”

“I haven’t had a lot of time to think about it, but I’m happy. I’m really happy that I was able to finish it off.”

The 32-year-old American becomes the eighth female to clinch 11 or more titles in a year (including two Grand Slams) and the first since Martina Hingis claimed 12 in 1997.

“I’ve just had a really long year, and I’m just really excited, honestly. I really didn’t expect to get through this match today,” added Williams.

“I can’t believe I won. I was so tired. Honestly, did I really win? Because she played well.”