LONDON — Liu Xiang slowly, awkwardly made his way alongside the track he was supposed to be racing on Tuesday, forced instead to hop on his good leg while straining to keep his injured one elevated.
Eight years ago, he won the 110-meter hurdles at the Athens Games — tying the world record of 12.91 seconds, giving China its first Olympic gold medal in men’s track and field, and almost instantly becoming one of the most famous and popular people in a nation of more than 1 billion.
The numbers since then for Liu? Two Olympics, zero hurdles cleared.
Liu stumbled into the first barrier of his opening heat at London’s Olympic Stadium on Tuesday, crumpled to the ground and stayed down for a few moments, clutching his lower right leg. The head of China’s track team, Feng Shuyong, said Liu might have ruptured his right Achilles’ tendon.
It was remarkably reminiscent of what happened in front of a stunned-into-silence home crowd at the Bird’s Nest in Beijing at the last Olympics in 2008, when Liu withdrew from his preliminary heat after taking all of two full strides, unable to overcome right foot and hamstring injuries.
This was supposed to be a chance to restore his reputation.
Instead, it was a near-repeat.
‘‘I’m very sad about this outcome, but I’m also proud of him, because Liu Xiang, from 2008 to now, has worked bitterly hard to take part in these Olympic Games. He has given so much,’’ Feng said. ‘‘In the struggle with his injury, he has overcome one difficulty after another and got back to a pretty good level, but at the crucial juncture of the Olympic Games, he got injured again.’’
‘‘For him to push himself and come back . . . and for this to happen — it’s really sad for any athlete,’’ Usain Bolt said after slowing to a jog and still easily winning his 200-meter qualifying heat Tuesday.
Back in China, Central Television commentator Yang Jian cried out and began to choke up when Liu fell during the live broadcast.
On Tuesday, Feng was asked whether the 29-year-old mentioned retirement.
‘‘It is not the time to talk about that,’’ came the reply.
Liu did not speak to reporters, whisked away from the stadium in a car.
Ivan Ukhov of Russia won the high jump in cold conditions and a light drizzle.
Ukhov, who earned a ‘‘strong warning’’ from the IAAF for being drunk during a competition in 2008, cleared 2.38 meters on his first attempt.
He had one failed attempt at 2.40, an Olympic record, before putting his warm clothes back on and starting the celebrations.
The 2010 world indoor champion was the leading performer in 2012 and held his nerve as Erik Kynard, the 21-year-old American from Toledo, raised the height late in the competition to try to get ahead of him.
Kynard took silver at 2.33 meters.
Three men tied for bronze: Essa Mutaz Barshim of Qatar, Robert Grabaarz of Britain, and Derek Drouin of Canada.
Robert Harting of Germany added the Olympic discus title to his two world championship golds, beating Ehsan Hadadi of Iran into silver.
Defending champion Gerd Kanter of Estonia took bronze.
Kanter, who ripped off his shirt in celebration, threw 68.27 meters for victory and extended his unbeaten record, which stretches back to August 2010.
Hadadi, who finished third at the 2011 world championships, finished with a throw of 68.18 and Kanter threw 68.03.
Schwazer is sorry
Italian race walker Alex Schwazer says he obtained the performance-enhancing drug EPO on his own and used it because he felt pressure to win a second straight 50-kilometer walk gold at the Olympics.
Schwazer, who was expelled from the games Monday for doping, sobbed on Italian TV on Tuesday. He insisted he won his gold at the 2008 Beijing Olympics without the use of drugs. He says he ‘‘wanted the gold again at all costs.’’
Schwazer says he learned how to use EPO via the Internet, and that the last three weeks after the doping test were ‘‘terrible’’ because he knew the results would be positive. He said he is ‘‘sorry.’’