by Scott Gullan in London
USAIN Bolt has failed to complete his final race.
In a shocking end to his brilliant career the greatest athlete in history suffered a leg injury half-way down the home straight in the final leg of the 4x100m relay.
Bolt received the baton in third position and as he attempted to switch gears something went horribly wrong.
The eight-time Olympic champion appeared to strain the calf of his left leg which threw him off balance.
Momentum saw him do a forward roll but he didn't last long on his feet before collapsing on the track.
He lay there motionless for some time as medical officials rushed to his aid, bringing a wheelchair onto the track.
Bolt shook them off and hobbled over the line, clapping to the crowd as he crossed finish line.
"It's a cramp in his left hamstring, but a lot of the pain is from disappointment from losing the race,” Jamaican team doctor Kevin Jones said. "The last three weeks have been hard for him, you know. We hope for the best for him.”
It has been a disastrous farewell championships for the world's fastest man who was surprisingly beaten in the 100m, his final individual race of his career, where he took bronze.
"It just happened,” Jamaican leadoff runner Omar McLeod said. "Usain Bolt's name will always live on.”
With Jamaica, who had won the previous four world titles out of the picture, it was left to hometown heroes Great Britain to take gold ahead of the USA.