Li Na lost her first match before home fans since winning the French Open, extending her inconsistent form with a loss to Romanian qualifier Monica Niculescu in the first round of the China Open on Sunday.
The fifth-ranked Li fell 6-4, 6-0 to the 58th-ranked Niculescu, disappointing the crowd on hand to watch her first tournament in China since winning in Paris.
The 29-year-old Li has lost in the second round at Wimbledon and the first round of the U.S. Open since becoming the first Chinese player to take a major title at the French Open in June.
In other matches, former No. 1 Ana Ivanovic defeated Japan's Kimiko Date-Krumm 6-1, 6-1, while another hometown favorite, wild card Zhang Shuai, lost to Dominika Cibulkova of Slovakia 6-0, 6-2.