Shortly after the Jamaican great won a fourth 200-meter title and a 10th gold overall at the world championships, a cameraman on a two-wheel vehicle banged into Bolt from behind.
Suddenly, the Olympic champion was down on his back, flipping over before getting back on his feet and then briefly holding his left leg. After regaining his composure, he walked back to the cameraman to make sure he was OK, too.
"It took me out pretty well," Bolt said. "But I'm OK. No issues, so I'm happy about it."
The unrivaled Jamaican outran Justin Gatlin again on Thursday in another sprint showdown. After bursting through the bend and powering down the finishing straight with no one close, Bolt had time to look left for Gatlin's red jersey. With nothing in sight, Bolt lifted both arms and punched his thumbs into his chest to show once again he is the greatest sprinter of all time.
"There was no doubt," Bolt said after winning his fourth 200 world title in a row to add to two Olympic titles. "I told you guys that I would do it."
He capped his performance with his trademark "Lightning Bolt" pose. After two years of doubt and worries that age had started to affect the bearded champion at 29, he again displayed the wide grin of a teenager.
With the clock reading 19.55 seconds, Bolt set the best time of the season. And despite slowing down, he still beat Gatlin by .19 -- much more than the .01-second edge Bolt had in Sunday's 100 final.
This season was supposed to be Gatlin's best chance to challenge Bolt, and despite the best times of his career at 33, he still came up short when it counted.
"I am the oldest man in the field and still running," Gatlin said. "Running pretty well."
Bolt is now 2-0 in Beijing against Gatlin, who had been unbeaten in two seasons, with only the 4x100 relay to come on Saturday.
Once Bolt sat down to savor his victory on a trackside chair, the American came over to congratulate him, and the two rivals shook hands and chatted.
Their rivalry in Beijing had been cast by some as "Good vs. Evil" because Gatlin served a four-year doping suspension midway through his career. By the end of their second showdown, however, they were joking with each other like boyhood buddies.
Explaining the cameraman incident to reporters, Bolt said: "The rumor I'm trying to start right now is that Justin Gatlin paid him off."
Gatlin, sitting beside him, retorted: "I want my money back. He didn't complete the job."
Seven years ago, Bolt started his amazing run of gold at the Beijing Olympics and has not lost a major 200 race since. The Jamaican, however, had been struggling with injury since winning his third straight 200 title at the 2013 world championships in Moscow.
Behind Gatlin, Anaso Jobodwana won bronze with a South African record of 19.87.
In the absence of gold from Gatlin, triple jumper Christian Taylor and Allyson Felix made up for it for the United States, both with superlative performances.
Taylor produced the second-best triple jump of all time with a leap of 18.21 meters on his final attempt to pad his lead over rival Pablo Pichardo of Cuba.
The 2012 Olympic gold medalist and 2011 world champion has been in a duel all season with Pichardo, with both clearing the 18-meter mark in the past two months to raise the prospect of the world record falling in Beijing.
In the end, Taylor narrowly missed the 18.29 world record which Jonathan Edwards set at the world championships in Gothenburg in 1995. Pichardo took silver at 17.73.
In the race preceding the men's 200, Felix won her first gold medal in the 400 meters and ever so briefly matched Bolt's record of nine golds in the world championships. A few minutes later, Bolt pulled away again with his 10th.
On a night of great performances, Anita Wlodarczyk broke the championship record twice on consecutive throws to win her second world title in the women's hammer throw with a mark of 80.85 meters.
The 30-year-old Polish thrower set the world record of 81.08 meters on Aug. 1.
Zhang Wenxiu of China won the silver medal in 76.33, ending a sequence of three consecutive bronze medals at the worlds. Alexandra Tavernier of France was third at 74.02.
Bolt beats Gatlin, takes 200 meters
ESPN senior writer Bonnie D. Ford discusses Usain Bolt's dominance following the Jamaican sprinter's victory over rival Justin Gatlin in the 200 meters at the world championships, as well as his collision with a photographer after the race.