WUHAN -- While Wuhan is hosting its first ever WTA premier-level tournament, Li Na, unquestionably the biggest reason for Chinese fans to watch it, announced retirement on Friday due to persistent knee injuries, which put an end to Asia's most successful tennis career.

"It's just like the heartbeat of Chinese tennis paused for a moment," said a local fan who showed a photo of his ticket for the Wuhan Open on Sina Weibo, China's Twitter-like social networking site.

"I had previously thought Li Na would secure a top-three finish in this home tourney and we would all cheer for her," said Xia Xiyao, the coach who introduced a six-year-old Li to tennis in Wuhan in 1988.

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"But now I feel sorry for her and I guess the injuries must be very serious."

Fabrice Chouquet, international consultant of the Wuhan Open, told a press conference late Friday that "the tournament is saddened by Li Na's decision to end her playing career due to injury. We know she will remain a key part of the Wuhan Open for years to come."

Yi Guoqing, the event director of the Wuhan Open, however, tried to play down the impact Li's absence would have on the tournament, saying "such uncertainties do exist in international competitions" and people who love tennis would be able to see top players like Serena Williams as well.

Had it not been for Li, China's only two-time Grand Slam-winner, sports authorities in her hometown would have never imagined hosting a top-level event, with Serena Williams, Maria Sharapova, Simona Halep, Petra Kvitova, Agnieszka Radwanska, Angelique Kerber, Eugenie Bouchard and Jelena Jankovic among the star-studded line-up.

"I'm sorry to see Li Na retire right before the Wuhan Open, but I know it must have been difficult for her to make the decision," said Hu Dechun, chief of Hubei Provincial Sport Bureau.

"Anyway, thank Li Na for her global influence, which made the WTA tournament possible in the city and also helped Wuhan attract one of the strongest fields ever assembled at a WTA event," he said, "and thank her for ushering a new era in Chinese tennis."

Tennis was once considered an elite sport in China. For the relatively high costs players have to face for rackets and court fees, it is much less popular than table tennis, basketball and football. But when Li Na showed up, things started to change.

Just as Yao Ming whipped up a basketball fever, Li has continuously inspired the new generation of tennis players in her hometown as well as in the country.

"I've succeeded on the global stage in a sport that a few years ago was in its infancy in China," Li said in her farewell letter posted on Sina Weibo. "In 2008, there were two professional women's tennis tournaments in China. Today, there are 10, one of them in Wuhan, my hometown. That to me is extraordinary!"

Xia, who for decades has coached young kids in a local tennis school, told Xinhua that "in recent years, a lot of parents have come to me saying how much they admire Li Na and want their children to play tennis and make a fortune like Li Na."

"But I usually told them Li Na is rare and unique," she said.