Usain Bolt's final appearance on the track has ended in agony, after he pulled up injured running the final leg of the World Championships 4x100 metres relay in London.
Jamaica had seemed assured of a medal, but Britain went on to beat the United States for a shock gold on Saturday night (local time).
Bolt, who had to settle for bronze in the individual 100m, had been hoping to sign off from the sport by leading Jamaica to a fifth successive relay gold but they were already struggling in third when he collected the baton.
The 30-year-old, straining hard to catch the leaders with 50m to go, suddenly suffered cramp in his left hamstring.
He began hobbling and ended up coming to a halt after doing a forward roll on the track.
The United States, with individual gold and silver medallists Justin Gatlin and Christian Coleman running the second and fourth legs, had been expected to push the Jamaicans all the way.
Instead, a brilliantly executed race by Chijindu Ujah, Adam Gemili, Danny Talbot and Nethaneel Mitchell-Blake gave Britain gold in 37.47 seconds, the best time in the world this year.
The US took silver in 37.52s, with Japan third in 38.04s.
As the race ended, Bolt lay on his back in his lane, his head in hands, being tended to by medics as one waited with a wheelchair to help push him off the track.
Yet the sport's greatest entertainer was determined that one of the finest careers in sport was not going to end with him in a wheelchair.
So the fastest man of all-time, surrounded by his three worried team-mates, Omar McLeod, Julian Forte and Yohan Blake, rose gingerly to his feet and limped the last 30 metres to the line to huge cheers from the 56,000-strong crowd.
The official result recorded that the Jamaicans did not finish, but Bolt had been absolutely determined to ensure he completed the last race after a matchless career in which he won 19 major championship gold medals.
Typically, Bolt's only thoughts were with the team-mates he felt he had let down. "He kept apologising to us but we told him there was no need to apologise," Forte said. "Injuries are part of the sport."
McLeod added: "It just happened - Usain Bolt's name will always live on."
TV scheduling to blame - Gatlin
Bolt's team-mates complained that a 45-minute wait in the call room before the race had hampered their preparations and contributed to his inury.
"I think they were holding us too long in the call room," Blake told reporters. "Usain was really cold. In fact Usain said to me ‘Yohan, I think this is crazy’. Forty minutes and two medal presentations before our run."
Gatlin, who beat Bolt to gold in the individual 100m last week, paid tribute to his rival. He agreed with the complaint, laying the blame at the television scheduling for the event.
"I think it was the elements (that caused the injury). I'm sorry he got this injury. He is still the best in the world.
"I know it’s TV magic, and everybody has to be prepared on time to make everything happen for the viewers at home.
"(But) I personally think that we were held in the stadium a little too long without our clothes on, and there was a little draught in there. I lost all my sweat and body heat," Gatlin said.
Team manager Ian Forbes praised Bolt for "going out there and giving his all" and added that the squad were "very saddened".
"The diagnostic work will be done shortly to determine how serious it is. He was able to walk to the team bus so hopefully that signals it's not as serious as it possibly could be."
