Retired Chinese tennis star Li Na, who is credited with introducing the game to the country's masses, announced Wednesday that she and her husband have a newborn daughter.

"Jiang Shan and I would like to introduce our Alisa to my lovely 'Na fans'," the 33-year-old wrote in an early morning posting to China's Twitter-like Sina Weibo.

"We are happy and we love her very much," she said, though did not specify when she was born.

A picture of a red baby footprint was attached under the message.

The announcement attracted more than 15,000 comments and was re-posted over 21,000 times in less than five hours, with web users expressing their congratulations and best wishes.

"Congratulations Li Na on your Grand Slam in life," said one user.

Another wrote: "Wish Alisa the happy little princess to grow up healthy and strong."

Li, who won nine titles in her career -- including the Australian and French open -- unexpectedly retired in September.

She announced her pregnancy in January in front of 15,000 cheering fans at the Australian Open, where she was a guest of honour, saying she has long wanted a child and to be a stay-at-home mum.