China's Li Na beat World Number 1 Victoria Azarenka Saturday 10-6 in a play-off after the pair shared a set each in a see-sawing invitation match in the Thai resort of Hua Hin.

Li, who became China's first superstar tennis player after winning the 2011 French Open, took the first set 3-6, dominating the World Number One Azarenka on the hard court with her serving and groundstrokes.

Azarenka sprung to life as the hot Thai sun faded and the flood lights came on, belting a series of winners as she claimed the second set at a canter 6-2.

But the Australian Open champion, who secured the top ranking when she beat Li in October at the WTA Championships in Istanbul, stumbled in the play-off making a costly series of unforced errors while Li plugged away, probing from the baseline.

Azarenka has experienced a huge reversal of fortunes in the last year or so, banishing doubts over her future in the sport with a crushing win over Maria Sharapova in Australia to kick-start a season in which she topped the world rankings.