(CNN) -- Six-time Olympic champion Usain Bolt was beaten into second place by Justin Gatlin in the 100 meters at the Diamond League's Rome meeting.
The Jamaican, who won three sprint gold medals at the London Games, lost out to his American rival who clocked a time of 9.94 seconds. Bolt finished 0.01 secs behind.
Bolt was making his first appearance in the competition this season after a hamstring injury kept him out of previous events in Qatar and Oregon.
"I got the perfect start that I wanted, then about five steps in I stumbled a little bit and that kind of threw my game off," Bolt told the BBC.
"My legs didn't feel like my legs coming into the straight. It's one of those things. I need to do more strength work, I guess. At least I got under 10 seconds.
"I think I just need time to get it back together, this season for some reason it goes right back to ground zero. I think the fact I got a good start threw me off, then I was all over the place and at the end it just wasn't me."
Bolt enshrined his legacy as a sprint great when he successfully defended his 100m, 200m titles at the 2012 Olympics, as well as the 4x100m relay with his Jamaican team.
He recently spoke of his desire to do the same at the Rio Games in 2016, which he predicted will be his last appearance at the event.
Gatlin, who served a four-year ban after testing positive for banned substances, was satisfied to beat the world record holder.
"It feels good," he told the BBC. "I put together my race strategy, and I'm not really worried about who is in the race.
"Usain Bolt is a great competitor and great champion so to come out here and have a victory it just stands that I'm having a good season.
"I just want to be confident and dominant when I run no matter what the time is. It's not about 9.6 or 9.7 at this point in time it's about putting on a great show for the fans.
"You can never count out Usain, he lost both races at his nationals last year and came back and was Olympic champion in both races. You just have to go in there with a great strategy and hope it works."