Li Na suffered a nightmare first round defeat at the China Open on Sunday as she went down 6-4, 6-0 to 58th ranked Romanian Monica Niculescu on an expectant centre court.
The world number five, making her first appearance in China since winning the French Open this year, dropped serve repeatedly as her slump in form continued.
Qualifier Niculescu romped away with the match after taking the first set, leaving Li, and the fans at the newly-opened National Tennis Centre, stunned.
Since winning the French Open to become the first player from an Asian country to win a grand slam singles title, Li has managed just five victories and suffered a second round defeat at Wimbledon and a first-round exit at the U.S. Open.
Chinese wildcard Shuai Zhang also fell in the first round, losing to Dominika Cibulkova 6-0, 6-2.
Former world number one Ana Ivanovic beat Japanese veteran Kimiko Date-Krumm for the loss of just two games while Wimbledon semi-finlalist Sabine Lisicki progressed when Romanian opponent Irina-Camelia Begu retired midway through their contest.
Aisam gets Federer, Nadal support for flood victims
Wozniacki rocks New Haven after earthquake
Images: Venus withdrawal eclipses U.S. Open action
PHOTOS: Short or skimpy, it's fashion at US Open
PHOTOS: Famous faces at Flushing Meadows