Bolt keeps a cool head in battle of wits with Gatlin
In the battle of two champions, it was the man who kept his head better who reigned supreme, Usain Bolt retaining his world 100m title in the Bird's Nest Stadium by flying to victory in 9.79 seconds.
Back in second, Justin Gatlin was left with nothing but regret after losing his head, his composure and his technique over the final 20 metres, the American essentially gifting the race to his Jamaican nemesis by flailing away the lead in his desperate bid to reach the line.
Given that Gatlin has served two doping bans and is now running faster than ever at 33, many in the stadium breathed a sigh of relief at the result -which, if not exactly restoring the credibility of sprinting, at least saved its reputation from plunging to an irretrievable low.
For Bolt, who has now put himself into unreachable territory as the best sprinter - and perhaps athlete - of all time, the result came as no surprise.
"If you have doubts, you've already lost the race," he said. "I know my ability. I just had to put together a great race. It wasn't perfect, but it was enough."
Beforehand, Bolt appeared the least nervous person in the stadium, joking with the cameraman and karate-kicking the air.
Gatlin, meanwhile, prowled with the determined menace of a hunter, one looking to not just overcome, but utterly annihilate his rival.
In the semi-finals, that looked a foregone conclusion: the American blasted home in 9.77 seconds; Bolt stumbled out of the blocks and came from behind to scrape victory in 9.96.
But in the final, when the gun fired and broke the deathly silence in the arena, Bolt rocketed away, running alongside Gatlin for the first half of the race.
That was a position the American was most unfamiliar with, given he has obliterated all challengers for the past two seasons. When Gatlin got to 80 metres, perhaps holding the slight advantage, his arms tightened, his torso leaned, and he slowed noticeably, allowing Bolt to power past and take victory in what was by far the closest race in his glittering championship resumé - 9.79 to 9.80.
"I could see myself get him at 80 metres," said Bolt, "and I was reminding myself to stay relaxed, keep my composure. I knew what it takes and I did what I have to do."
Gatlin looked disgusted after losing his unbeaten run, but the American was gracious in defeat. "If I had to lose to anybody, I'm glad it was to this man," he said.
For Bolt, the victory silenced many of the doubters who had forecasted his decline, and he will now get the chance to earn more gold later this week when he renews rivalry with Gatlin in both the 200m and 4x100m relay.
Bolt was nowhere near his best, but it didn't matter. It was enough, for now, to defeat the man the sport needed to be defeated. It was a chink of light emerging in the darkest of summers for athletics.
Meanwhile, Jessica Ennis-Hill has completed her golden comeback, winning her first major championship since London 2012 just 13 months after the birth of her son.