Yao, the tallest athlete ever to compete at the Olympic Games, sparked a 10-0 scoring run late in the fourth quarter after China trailed most of the game to clinch the final quarter-final spot.
"We did not want to pack up our things and leave (the Olympics) today," the 2.29 metre (7 feet 6 inches) centre said. "I really don't know what words to use to describe this."
He could start by using the word shocked.
FREE THROWS
That is what Serbian coach Zelimir Obradovic used to describe the outcome of a game where his team led most of the way only to see Yao hit a pair of free throws with 28 seconds left to give China the lead for good.
"This is a big shock for us. For me, it is the hardest moment of my career.
Serbia and Montenegro came into the tournament with high hopes. The team was widely considered as a medal contender even though two of its NBA mainstays -- Sacramento King's forward Peja Stojakovic and Los Angeles Lakers centre Vlade Divac -- opted out of playing.
But a tournament opening loss at the buzzer against Argentina set the tone for Obradovic's team, which fell short in the dying seconds to Italy and New Zealand as well to close with a 1-4 record in the preliminary round.
"I don't quite understand the way I feel right now, but I do understand the way he (Obradovic) feels," said Chinese coach Del Harris, an NBA veteran with more than 45 years of coaching under his belt. "This is the best win I have ever had."
China, which placed 10th at the Sydney Games and filled the team with a group of younger players with an eye on Beijing 2008, will play Lithuania in the quarter-finals which begin on Thursday.