The controversial Gatlin came into the final on a 28-race unbeaten run and apparently relishing his role as the sport's bad guy.
But at the same Bird's Nest stadium in Beijing where Bolt announced himself to the world with two Olympic golds and two world records in 2008, the Jamaican superstar came past a faltering Gatlin at the death to snatch victory by one hundredth of a second.
Bolt's 9.79 seconds was more than two tenths off his world record, but this was a night for athletics to celebrate victories rather than times.
