LI Na was not the most successful women's tennis player of her generation, but she may well turn out to be the most influential.

The 32-year-old Chinese, currently ranked sixth in the world, announced her retirement last week after giving in to the knee injuries that plagued her career. She won two grand slam tournaments - the 2011 French Open and this year's Australian Open - and rose as high as No.2 in the world, but her legacy may reach far further than her on-court achievements.

Li was something of a late bloomer in tennis - she had to wait until her late twenties to hit her peak and when she won her maiden grand slam title at the age of 29, she became one of the oldest first-time female winners of a major in the open era.

It was that victory which catapulted her to superstar status within her own country. She became the world's second highest-paid female athlete (after Maria Sharapova) and, as with all Chinese athletes who excel at sports in which the west commonly dominates, Li had no shortage of interest from international companies, signing deals with behemoths such as Rolex, Mercedes-Benz and Samsung.

Additionally, Li was one of the very few Nike-sponsored athletes who was permitted to wear the badge of other companies on their sports clothing, such was her worth to the American clothing giant.

While Li's standing as the most prominent Asian player on the tennis scene brought her many endorsements, it was her personality which generated much interest. Her streak of individualism attracted considerable criticism from China's state-run media, and this criticism only intensified when she left the Chinese sports system in 2008.

Li disliked the rigidity of the national system - it controlled everything for the athlete and included strict rules. This included no relationships between team-mates, a rule Li duly ignored; she met her husband as a 16-year-old while training alongside him at the national centre. But this was not the only rule which she defied.

As part of a system in which dissent is almost unheard of, Li first challenged her coaches when she was 11 years old. During a coaching session, on the verge of exhaustion, she refused to continue training - her punishment was to stand motionless in one spot until she retracted what she had said. Li stood in that spot for three days before she apologised. That stubbornness would prevail until the end of her career.

The Chinese government demands that athletes whose development they have helped give back 65% of their earnings to the federation. Li fought this, in the end brokering a deal which allowed her to 'fly solo', meaning she could hire her own coaches, set her own schedule and, most importantly, keep a greater percentage of her earnings. For the remainder of her career, Li paid only 12% of her earnings to her federation.

But it is Li's prominence at the top of the women's game which is likely to prove most significant. She was not the only Chinese player to compete at world-class level, but she was the one who really excelled. While Zheng Jie and Peng Shuai both reached the world's top 20, it was Li who made the breakthrough, which triggered an explosion of interest in the game in China.

In 2009, less than five million out of a population of one billon played tennis in her homeland. Now, according to the WTA, that figure is more than 10m. In 2008, only two WTA tournaments were hosted by China; this season, there were 10, including one in Li's home province of Wuhan.

The increased profile of tennis in the country as a result of Li's success is remarkable with more than 116m Chinese viewers watching her win the French Open title in 2011.

Currently, there are few, if any, ready-made successors to Li's crown and it may be a decade or more until her real legacy becomes apparent. Her importance to tennis was perhaps best summed up by Stacey Allaster, CEO of the WTA, when Li first rose to prominence.

"If the Williams sisters had the greatest impact on the first decade of this century," she said, "then I would say, without a doubt, that Li Na will be the most important player of this decade."