(CBS/AP) Some of the most enduring Olympic moments are also the most heartbreaking. At the 1992 Olympics in Barcelona, injured British runner Derek Redmond limped to the finish line with the aid of his father. Just two days ago at these 2012 Games, Canadian triathlete Paula Findlay, who was battling an injured hip, refused to give up despite finishing in last place.
And now we can add Liu Xiang to the list of inspiring Olympic athletes. The former champion left the Olympics Games in the first heat of the 110-meter hurdles for the second time in a row, clutching his right Achilles after he crashed into the first obstacle.
Moments earlier, he produced a wan smile when the stadium speakers announced his name to the cheering. He was talking to himself as he started to settle in the blocks.
Then from the starting gun, it all went wrong. With his lead leg, he crashed into the first hurdle and tumbled over. He looked up and held his right leg, realizing history has just repeated itself.
But it's what Liu did following his injury that was so memorable.
Instead of being wheeled off, he decided to hop on one leg along the track and went over to kiss the last hurdle in his lane 4. He then labored to the finish line on one leg.
When that slow, awkward trek was complete, another hurdler, Balazs Baji of Hungary, went over and raised Liu's hand in the air, as if to signify he was the winner.
"I respect him. I like him," said Baji, fifth in their heat. "It must be really bad for him. I'm really sorry. I didn't say anything. I just couldn't say anything."
Britain's Andrew Turner and Spain's Jackson Quinonez then led him off to a waiting wheelchair.
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Liu won in 2004 at Athens to become the first Chinese man to claim an Olympic track and field gold medal, but shocked the home crowd in Beijing four years later when he had to withdraw in his heat without clearing a hurdle because of a right foot problem which later required surgery.
This time, his coach had already expressed concern that Liu was less than fully fit, but still he had been expected to challenge for gold again in London.
His fall shocked and saddened supporters in China who were posting bawling emoticons on the microblogging site Sina Weibo, where the topic was trending.
"I have to admit, I cried at that moment," blogger Little Actor Zhou Xuanqi wrote. "I wish he could recover soon."
The fastest man on Earth was moved by the moment.
"It's really hard, I think he's one of the best. He's showing the world he can do great things," Bolt said. "For him to push himself and come back last year and for this to happen, it's really sad for any athlete."