"He couldn't imagine the pain he was suffering," coach Feng Shuyong said at a news conference Liu didn't attend. "Let me repeat: Liu Xiang will not withdraw unless the pain is unbearable."
While the other entrants in his heat prepared for the restart, Liu took a slow, painful walk along a concrete path leading away from the rust-colored track where he was supposed to thrill a nation of 1.3 billion people.
Instead, he sat against a wall alone, that smiling face that adorns so many advertising billboards now sullen. At that moment, some members of the Chinese media watching the scene unfold on a TV under the stands began to cry while thousands of his disappointed countrymen were heading for the exits.
"I feel very sad for Liu Xiang," said 67-year-old retiree Liu Guixiang. "After Liu Xiang's injury, I won't bother coming back to the Bird's Nest for more."
Had this been any other competition, in any other setting, it seems safe to say Liu wouldn't even have shown up at the stadium himself on this day.
"When you see the crowd, you realize why he had to come out," said Britain's Allan Scott, who was surprised when he glanced across the lanes and didn't see Liu ahead of him in the final heat.
Liu's personal coach, Sun Haiping, said Liu was bothered by a right foot injury that has lingered for six or seven years - and that the pain intensified Saturday. Sun's shoulders shook and he wiped away tears as he spoke about Liu's withdrawal.
Feng said the injury is where the Achilles tendon attaches to Liu's right foot, "his takeoff foot, so there is a lot of stress on that area."
There were signs of trouble as soon as Liu made his first appearance on the Bird's Nest's big video screens. Once on the track, he stopped after clearing two hurdles during the warmup period, then crouched down and favored his right leg as he walked back to the starting area.
He peeled off his red shirt when others were lining up behind the blocks and seemed to wait forever before pulling a new jersey over his head.
"In watching warmups, we could see he wasn't quite as strong as you expect him to be," said former world record-holder Colin Jackson. "But we didn't know it was as bad as it turned out to be."
Liu's hamstring problem forced him to pull out of a meet in New York on May 31 - the same night Usain Bolt first broke the world record in the 100 meters.
A week later, Liu lined up for the Prefontaine Classic in Eugene, Ore., but was disqualified for a false start. He hasn't raced since and only rarely has made public appearances, training in seclusion.
The 25-year-old hurdler is as much a celebrity here as Houston Rockets center Yao Ming. At the Athens Games four years ago, Liu became as the first Chinese man to win an Olympic track and field gold medal. A Chinese insurance company volunteered more than $10 million of coverage for his legs. His image appears everywhere in his hometown of Shanghai, and he has sponsorship deals with Visa and Coca-Cola, among others.
"I think the Chinese people will understand the situation," Feng said of Liu's withdrawal, "and will encourage him to come back to the track."
Thursday night's 110-meter hurdles final was expected to be one of the highlights of these Olympics: China's Liu vs. Cuba's Dayron Robles, the man who broke Liu's world record in June - with 91,000 fans crowding into the Bird's Nest to cheer on their man.
"I think they will be disappointed," said Wang Wei, executive vice president of the games' organizing committee. "But they will understand. When somebody has an accident, you can't help it."
Now Robles, who won his heat but at 13.39 seconds was well off his world record time of 12.87, becomes the clear favorite.
Yet another of the top contenders departed Monday when two-time Olympic silver medalist Terrence Trammell of the United States grabbed the second hurdle and limped off the track with an injured left leg.
The exits of Liu and Trammell leave David Oliver, thought to be running as consistently as any of the U.S. hurdlers of late, as a serious medal candidate. His personal best of 12.95 seconds is only 0.08 second off Robles' world record.
Asked before Liu lined up for his heat whether he knew that his Chinese rival appeared to be hurting badly, Robles said he didn't care.
"I'm going to do what Usain Bolt did," the Cuban said when asked about breaking his hurdles world record. "The track is perfect. Anything is possible in the final."