Wang Chen of the United States defeated Kim Kyung-ah of South Korea on Thursday to become the first American in Olympic table tennis history to reach the quarterfinals.
All three Chinese players also advanced and kept alive the possibility of a medal sweep for the host team.
After her 4-3 win over Kim, the world's top defensive player, Wang collapsed to her knees next to the table and cried into her towel.
"I thought it was possible to beat her as long as I was full of confidence, because she's a defensive player," Wang said. She won 11-9, 9-11, 11-8, 10-12, 6-11, 11-9, 11-5.
Wang, who's ranked No. 23 in the world and runs a popular pingpong club in New York City, will go on to face sixth-ranked Li Jia Wei of Singapore on Thursday night.
The other American playing in the round of 16, Gao Jun, lost to Wu Xue of the Dominican Republic 12-10, 11-8, 6-11, 11-3, 8-11, 12-14, 11-9 in an hour-long match.
"I was just trying to fight. I was very tired, it was just such a long match," said Gao, who won a silver medal for China at the 1992 Barcelona Games before emigrating to the U.S. "I just couldn't move anymore. I missed so many points."
Meanwhile, the Chinese players were also victorious in their round of 16 matches, although fatigue was setting in on the ninth day of the Olympic competition.
"Physically (playing singles) is not as easy as (playing teams), where it's just one match a day. But you don't have a choice. You just have to adjust fast," said China's Wang Nan, a four-time Olympic gold medalist.
She won 11-7, 11-7, 9-11, 11-6, 11-13, 11-5 over South Korea's Park Mi-young.
Teammate Guo Yue defeated Li Jiao of the Netherlands 4-0. Top-ranked Zhang Yining eliminated No. 12 Ai Fukuhara of Japan with a 4-1 victory.
"I wanted to hurry up and win so I could go back and get some rest," Zhang said of her 11-5, 11-2, 11-5, 9-11, 11-8 win.
In men's singles, defending gold medalist Ryu Seung-min of South Korea was eliminated in the round of 32 after losing to Hong Kong's Ko Lai Chak, 11-7, 11-8, 11-6, 4-11, 5-11, 12-10.
Ryu has had a disappointing performance at the Beijing Olympics, losing five of his eight singles matches in the team competition.
"Even though there has not been a great deal of pressure on me, I have met many strong players in this tournament," Ryu said.
All three men on the Chinese squad _ Wang Hao, Ma Lin and Wang Liqin _ advanced into the round of 16, as did their top threats, Timo Boll of Germany and Vladimir Samsonov of Belarus.