Each team entered the day with seven points in the preliminary round. The top four teams in each pool, based on the points system, advance to the quarterfinals — the knockout round.
Normally, a team earns three points for a victory. But if the match goes to five sets, the winner is awarded two points and the loser earns one.
A five-set match was the only way mathematically for both teams to advance to the quarterfinals. Had one team won all three points, the other team would have had to depend on results later in the day.
China and South Korea were in the same pool as the United States, Brazil, Serbia and Turkey. Japan, Russia, Italy, Algeria, the Dominican Republic and Britain make up the other group.
Neither team made any obvious errors to push the match to five sets. China won it 28-26, 22-25, 25-19, 22-25, 15-10, taking match point on Xu Yunli's kill. Afterward, the Chinese donned special T-shirts and celebrated on the court.
In the post-match news conference, South Korean coach Kim Sil-Hyung acknowledged he knew that a five-match result would advance his team. Chinese coach Yu Juemin avoided the question.
When asked if there was any agreement beforehand to push the match to five sets, both coaches were emphatic.
"No, there's no such thing," Yu said.
"Of course not," Sil-Hyung said.
South Korea's top player, Yeon-Koung Kim, said she was not aware that a five-set result would secure both teams a spot. Kim finished the match with 32 points.
"We fight and they fight," she said.
South Korea was assured of at least a fourth-place finish in the pool, based on its eight points.
The undefeated U.S. women, who were set to face Turkey on Sunday night, had already clinched the top seed.
Still in question was the final team to advance in the pool.