Four days on from riding to the rescue of his beleaguered sport in the 100 metres, the Jamaican attempted to make it four successive half-lap world crowns in Beijing.
Gatlin, cast as athletics’ No 1 villain, again stood in his way but once more failed to wrestle away gold as Bolt held strong down the home straight to win with a world-leading 19.55 seconds.
The 29-year-old finished the 200m final an impressive 0.19 secs ahead of two-time drugs cheat Gatlin, whose comments in the build-up clearly irked the Jamaican sprint great.
“It was never a doubt to me,” said Bolt after the standard exuberant celebrations.
“Maybe I doubt a lot of people, but I never doubt that I will win my 200 metres.
“I wasn’t worried. I knew I had to run the first 150 hard. After the first 150, I looked across and I could see that Justin Gatlin was tiring and then it was never a doubt I would win the race.
“Why I really celebrated was because Justin Gatlin said earlier in the week that he was going to bring out something special for the 200 metres.
“I was like ‘yo, you don’t talk about my 200 metres like that’ so I had to prove to him that I am No 1.”
Those celebrations were, as always, lapped up by the crowd, with some of the “crazy fans” trying to get closer to the 200m champion by jumping the barrier.
They were swiftly ushered away by the stadium’s heavy-handed security team, although they could not protect Bolt from an unusual threat.
A TV cameraman was trailing Bolt’s celebrations when the wheel of his segway rolled up on to a camera track, changing the vehicle’s direction and taking the sprinter out from behind.
There was an audible gasp inside the Bird’s Nest as the double gold medallist was wiped out, but he quickly composed himself and allayed fears of any lasting impact afterwards.
“It didn’t actually hit me in my Achilles, it hit me in my calf area,” Bolt confirmed. “It’s alright, I will get over it.
“Never a doubt (for the relays), never a doubt. I am just going to get it massaged, ice it up a bit and I should be fine.”
The segway certainly had more of an impact on Bolt than main rival Gatlin.
The 33-year-old - like in the 100m - headed into the race as this year’s fastest man, but was reduced to silver for the second time this week.
“I went in there with my game plan which my coach set for me - run the curve, attack him up the curve and keep holding on,” said Gatlin.
“I think that he was in my window last night - he took the same strategy because when I came off the curve he was running right there.
“Coming home, I gave all I could give at this point in time. Now it is time to get some rest and get ready for the relay.”
The 4x100m relay promises to be another fascinating battle between Jamaica and the United States, with bookmakers making the latter slight favourites to top the podium.
Silver medallist Gatlin was the only American in the 200m final and was followed home by Anaso Jobodwana, whose South African record time of 19.87 pipped Panama’s Alonso Edward by just two-thousandths of a second.