Seven years ago in Beijing, Usain Bolt announced himself as the undisputed fastest man on earth, winning his first major 100 metres gold medal with such apparent ease that the big Jamaican could flamboyantly showboat across the finish line and still break the world record.

Not this time. Such was the challenge laid down by the American Justin Gatlin that Bolt had to run flat out all the way to the finish line, before hurling himself over it. Whatever about it being a triumph for good over evil, or indeed the hero over the villain, it was not just another World Championship 100m: it was one of the most perfectly necessary executions of the event ever seen.

It needed to be, too. Without it being so perfect, Gatlin would unquestionably have won, and with that his past doping offences would have lit up the story, much more than anything about the race itself. Bolt then not only saved the sport from some considerable embarrassment, he also did it with the style and pure competitiveness that have made him such a great champion.

Finish line

“I definitely think this was my hardest race,” Bolt duly admitted, after just about getting past Gatlin in the final few strides. Bolt ran his season best of 9.79, Gatlin finished in 9.80. Indeed the only time Bolt was in front, and not Gatlin, was coming over the finish line.

“I’ve been through a lot this season, it’s been rough,” said Bolt, who had missed a large part of it through injury.

“It definitely means a lot because I’ve been struggling. It took me a while to discover the problem. And it’s all held together, so I’m just happy.”

Yet afterwards, as before, Bolt was reluctant to be drawn into the Gatlin controversy, and what a victory for the two-time doping offender would mean.

“For me, I understand why, but I wanted to do it for myself. It was a big deal. Coming back from injury I’ve had a lot of doubters, it’s been a tough road, so for me to come to the championships and defend my title is a good feeling.

“I almost fell in my semi-final. But after that my coach [Glen Mills] said, ‘Listen, you are thinking about it too much, there’s too much on your mind, all you have to do is remember that you’ve been in this position way too many times, you’ve done this a million times so just go out there, relax and get it done’. And that’s what I did.”

Indeed Bolt’s good start was every bit as crucial as his finish, as Gatlin, unbeaten in 27 of his previous races, was typically swift out of blocks. He held the charge on Bolt all the way through to 90m, before his otherwise perfect technique suddenly abandoned him, perhaps his 33 years catching up with him too.

Stumbled

“Really, I gave it away,” Gatlin said. “I stumbled in the last five metres, my arms got a little flaily. But I’m happy to come so close and to represent my country.

“You have to come out and run and over the last five metres it wasn’t my day to do so. Whether he came out with his A game or his B game, I had to be on top of mine. I leaned a little too far forward, and I got a little off balance.”

Yet Gatlin was largely gracious in defeat, too, handing the credit to Bolt for winning what was his fifth major 100m title – back-to-back Olympic titles, and World Championship titles in 2009, 2013, and now 2015.

He’s only blip was in 2011, when he false-started in the final.

“He’s a gamer,” Gatlin said of Bolt. “He’s a showman. Anyone who goes to the line to go against him has to be ready to go to work. In those five metres I let things get away from me. I stumbled a little, and it cost me the race.”

Asked about his enduring unpopularity within the sport, Gatlin simply claimed he was “thankful” to his supporters.

And yet never has the sport needed to be more thankful to have Bolt back to his commanding best.