Usain Bolt went into his last-ever 100-metre race feeling less than confident – and the Jamaican legend’s premonition proved to be on the money as his ageing legs propelled him to a disappointing bronze in the men’s 100-metres final at the World Championships in London.

“I’m just disappointed I couldn’t do better, but that’s how it goes sometimes,” he said with a philosophical shrug.

With the image of dead friend Germaine Mason pinned to his singlet, Usain Bolt accepts the disappointed crowd’s love and applause.

The omens were there from the start for the eight-time Olympic gold medallist, who placed a disappointing second behind American Christian Coleman in the Saturday (UK time) semi-final.

“That was very bad, I stumbled coming out of the blocks … I have to get this start together because I can’t keep doing this,” he said, clearly worried that he had lost his winning edge.

Yet the same slow start also figured in the final – plus a characteristic burst of blinding speed that just wasn’t there.

Hailed by the crowd when he entered the stadium, Bolt’s loss was marked with even louder and more prolonged applause after the race, while winner Justin Gatlin, 35, was booed.

The US veteran, who was banned from the sport for four years after being found guilty of doping in 2006, took the gold with a 9.92 second dash, heading fellow American Christian Coleman on 9.94 seconds.

Bolt crossed the line in 9.95 seconds as the fairytale ending to a lustrous, incredible career failed to materialise.

“I tried and I tried, but not enough,” Bolt said after the event.

“We’re competitors, Justin and me, and he was better on the day.”

A bemused Usain Bolt accepts the tribute of the man who beat him, American Justin Gatlin.

Despite the crowd’s boos, Gatlin was gracious in victory — dropping to his knees in front of the vanquished champion to pay homage to the man he had just beaten.

Bolt, 30, won every Olympic and world 100m and 200m since 2008, with the exception of the 100m at the 2011 Daegu world titles, when he false-started in the final.

Bolt is also scheduled to contest the 4x100m relay on the penultimate day of the championships which run until August 13.

The race ended as it began, with American Justin Gatlin (in blue) snatching an early lead over Bolt (in yellow at rear) and retaining it throughout.

The stunning loss left spectators wondering if a badge pinned to Bolt’s singlet told the story of his failure to end his career with a winner’s laurels.

The badge bore the image of a man’s face and just two words “Germaine Mason” — the name of the sprinter’s best friend who died in an April motorcycle crash in the Jamaican capital of Kingston..

Bolt had been out on the town with his British high-jumper mate that same evening and was one the first on the scene after the fatal crash.

“Mentally, I wasn’t ready to even train for, like, two and a half weeks, which I had to take off and just collect myself,” he said after returning to training.

“So I have been working hard trying to get back to where I was.”

Might the lost weeks of training have made the difference, sliced those couple of hundredths of seconds off his time?

Unlike the certainty that we will never again see the likes of the Usain Bolt in his prime, we will never know.

– with AAP