The world record holder defied the atrocious conditions to blaze to victory on a drenched blue Mondo track at the Luzhniki Stadium in 9.77 seconds, his best time of the year.
He held off the challenge of Gatlin, who clocked 9.85secs, with Bolt’s fellow Jamaican Nesta Carter getting bronze in 9.95s.
Bolt performed all his customary pre-race preening, pretending to hold up an umbrella, all part of the show from the born entertainer but when it came to the crunch he was, as always, ice cold.
He was out of the blocks well and, just as it looked as if Gatlin, in the lane inside him, might be closing, he pulled clear to reclaim the title he lost after that sensational false start in the final in Daegu two years ago.
“It was not a revenge for Daegu, I just came here to win this title,” said Bolt afterwards.
“I wanted to do a better time, but was not able to because of the weather.
“This is just one of those days – not ‘singing in the rain’, but ‘running in the rain’.”
Gatlin added: “We saw the lightning on the horizon when we were on the warm-up track. Then we saw the tent rattling and I thought they were going to postpone the race.”
It takes more than a spot of thunder to put Bolt off his game, though.
This final had been headed for a mouthwatering showdown between Bolt and a rejuvenated Tyson Gay, before the latter’s failed drug test sent shock waves through athletics.
Former world record holder Asafa Powell’s failed test was confirmed hours later and the sport was on its knees.
So it was perhaps apt that last night’s race was a head-to-head between Bolt, the saviour of the sport, and Gatlin, who has twice served drug bans, including a four-year suspension, which ended in 2010.
The American had beaten Bolt by a whisker at a Diamond League meeting in Rome at the start of the season, but the world stage is where the world record holder feels at home.
“It was an average start and that, for me, is a great start,” said Bolt.
“Around great starters like Gatlin and Carter I knew I had to get it right. I knew Gatlin was not going to crack under pressure so I had to stay focused and run to the line.
“I said to Gatlin I always appreciate competing with him because he always comes out and gives it his best.”
Bolt had sauntered through his semi-final in 9.92 earlier in the evening, along with three compatriots.
In the end there were four Jamaicans in the top five, with Kemar Bailey-Cole fourth in 9.98 and Nickel Ashmeade fifth in the same time.
Britain’s James Dasaolu came home in eighth and will have been disappointed to not have bettered or even matched his semi-final time of 9.97 secs which got him into the final as a fastest loser.
It was his second sub-10 time of the summer, but he was unable to produce a third in the final, finishing eighth in 10.21 secs.
Dwain Chambers and Harry Aikines-Aryeetey failed to make it through the semi-finals
“The semi-final obviously took a lot out of me,” Dasaolu said after the final. “I gave it my best – all I could.
“I think I was with the field up until the final 50m, 60m, and then they started to run away from me.
“I just felt the semi took it out of me, but I made it through three rounds here and I am just happy to be injury-free and able to continue with the rest of the season.
“It is my first world final, it is a big achievement for me. At the beginning of the season, it was one of my goals along with going sub-10.”
It is difficult to imagine what the next serving from a “living legend”, as Bolt branded himself after his triple London 2012 triumph, will be, but everyone’s favourite Jamaican is on his way there.
By his own stratospheric standards, Bolt had between below par this season, his best time the 9.85 he ran to win the London Anniversary Games.
He is, though, quite simply on another level to his competition when it matters, and it showed.
“I am going to try continue winning championships. I want to be mentioned alongside greats like Pele, Maradona and Muhammad Ali,” he said.
And that could include the Commonwealth Games in Glasgow next summer.
“I have never been to the Commonwealth Games,” he said. “It’s something I’m thinking about, but I don’t know if I’m going to go yet. It would be something to add to my resume.”
The only negative was the fact that, yet again, the stadium was some way off capacity, hugely disappointing given last night’s action included Bolt and an appearance by Russian darling Yelena Isinbayeva in pole vault qualifying.
Tickets were still available for the 100m final for 300 Roubles (£5.88) just two hours before the blue riband event got under way.
Elsewhere, Christine Ohuruogu fired a warning shot to her 400 metres rivals with a dominant display that secured safe progression to the final.
The 29-year-old looks in the form of her life, following up a comfortable heats victory with a similarly impressive semi-final win. Ohuruogu crossed the line in a season’s best time of 49.75 seconds despite easing down at the finish and looks set to threaten Kathy Cook’s 29-year-old British record of 49.43 today.
One British medal hope to fall short yesterday was Shara Proctor in the long jump final.
The Anguilla-born athlete could only manage a best of 6.79m after going 6.85m in qualification – a distance which would have been enough to take bronze last night.
“As an athlete you have to have a short-term memory,” Proctor said. “Yesterday was in the past and I forgot about it and came here with a new mind-set to win a medal but it just didn’t happen.”
Olympic finalist Andrew Osagie produced a season’s best of 1:44.85 for fourth place to make the 800m final, but Michael Rimmer failed to progress from his semi-final.
Alex Wright finished 31st in the 20km race walk final, while in the morning session 2011 silver medallist Hannah England came through the 1,500m heats.
Nigel Levine reached the men’s 400m semi-finals with a comfortable fourth-place finish in 45.41 secs, while William Sharman and Asha Philip made the same stage of the men’s 110m hurdles and women’s 100m respectively.