Algerian middle-distance runner Taoufik Makhloufi was reinstated for the 1,500-metre final after he had been disqualified from the Olympics for allegedly not trying hard enough yesterday in the 800 heats.
Makhloufi had already qualified for today's 1,500 final, where he was a likely medal contender, when he stopped running in the first lap of his 800 heat.
The race referee ruled that the 24-year-old African champion in the 800 was guilty of "failure to compete honestly with bona fide effort".
The Algerian federation insisted he had a knee problem and organisers knew about it.
After assessing evidence of a Games medical officer, the disqualification was revoked, allowing the runner to compete in the 1,500 final. The concern over the injury was deemed genuine.
The head of Algeria's track and field federation said the team felt "really hard done" by the initial ruling.
Makhloufi "respected everybody in the race he was in. He presented himself to the race officials," Bahreddine Belhadjoudja told The Associated Press by phone from Algeria.
Makhloufi had already won his heat and semi-final in the longer event.
"He had a pain in his knee and wanted to save himself for the final," Belhadjoudja said.
Track and field's governing body reinstated the runner for today's medal race after "reviewing evidence" from a medical officer.
The runner's case was the latest flap at the Olympics about not playing to win, but this time the decision was revoked.
Last week, four women's badminton doubles teams from China, Indonesia and South Korea were disqualified for playing to lose to manipulate their likely route to the final.
The coach of Japan's women's team escaped punishment from FIFA and the International Olympic Committee after acknowledging that he instructed his team to not win a group match to influence where the team's quarter-final would be played.