British rider Chris Newton's hopes of a medal disappeared when he dropped out of the cycling points race.
The 2002 world champion pulled up just after halfway through the event when trailing well behind in the standings.
"I haven't got any explanation for how I felt out there. Things just went from bad to horrendous," said Newton.
The contest was won by Russia's Mikhail Ignatyev with Joan Llaneras of Spain taking silver and German Guido Fulst in bronze-medal position.
"I couldn't handle not being able to compete and I couldn't understand why I wasn't able to close the gap and why I wasn't sprinting well," said Newton.
"I just didn't want to finish last or 10th. I wanted to be in the medals," added the rider in explanation for pulling out.
"I couldn't face it any more. I wasn't riding like I know I can ride and like I expect to ride.
"Before the race I was totally relaxed and ready for the job. The top half was ready but the bottom half just didn't want to ride.
"It was an awful feeling and I feel for everyone who has helped me get this far."
Newton's disappointing performance mirrored that of British marathon hope Paula Radcliffe, who said she could not explain her poor performance and ultimate withdrawal from Sunday's race.
"It's a parallel we can draw maybe," admitted Newton's coach Simon Jones. "She can't explain it and sometimes you just can't.
"Maybe because he was one of the favourites, we put too much pressure on him. But it's very odd. I haven't experienced that before.
"The Olympics is so special that to come here and perform so unexpectedly (badly) with thousands of people watching has left him devastated."
It has been a disappointing Games for Newton, who was part of the team pursuit but who missed out on a silver medal because he did not ride in the final.
However, team manager David Brailsford said that an appeal had been launched to secure a medal for the rider.
"We made the same appeal in Sydney and it was successful so we hope for the same result this time," said Brailsford.