British number four Laura Robson was beaten in straight sets in the first round of the China Open in Beijing.
The 17-year-old, who came through qualifying, lost 6-4 6-3 to Slovenia's world number 35 Polona Hercog.
Li Na also went out in front of her home fans on Sunday as she was defeated 6-4 6-0 by Romanian qualifier Monica Niculescu.
World number five Li said: "I've lost all confidence. I don't know what I can do. Even winning one point is tough."
Li dropped serve six times against Niculescu and lost in just under 90 minutes.
"For me it seems like the end of the season right now," she added.
"I need a long break - for the body and the mind. Hopefuly I can start again and prepare for next year."
Hercog's reward for beating Robson is a tie with number two seed Victoria Azarenka.