Shrug replaces Usain's lightning Bolt as 'fastest man in the world' defeated by Justin Gatlin

'World's fastest man' beaten in to second place by American in Rome

Usain Bolt still manages to be a showman after an unexpected 100m defeat in Italy (Reuters)

This was not in the script. Usain Bolt, clad in an Italy shirt, was paraded around the Stadio Olimpico a full two hours before his race to rapturous applause. When he appeared for the business end of the event it was to screams of delight. By the end, all the man himself could do was shrug as Justin Gatlin danced around the Roman track in celebration of a rare triumph.

Gatlin had suggested the 100m was going to be a dogfight this year and that he was in the form to beat the Jamaican, and tonight he lived up to his promise, ducking ahead of Bolt to win in 9.94 sec, 0.01 sec ahead of the world and Olympic champion.

Bolt had arrived in Rome with a declaration of his own: that he wanted to dominate the four years that are left of his track career. He has started the season sluggishly – by his standards – but Rome has been where he has set his stall out for the previous two seasons. Instead it was Gatlin, the former doper who has started the season in scintillating fashion, who got his man.

"I really wanted to get a good start," said Bolt. "I got the perfect start but stumbled after five metres. It's just one of those things. I guess I need to be stronger at the end of the race. I think it's just time to get back. This season goes back to ground zero. At least I ran under 10 seconds this time.

"My legs did not feel the energy. It is just putting things together for the world championships. It is still very early. But you learn more from losing and you can't win every race."

It was his second race of the season after a 10.09sec in the Cayman Islands, and his first defeat over the distance since Yohan Blake got the better of him in the Jamaican trials before the London Games. Bolt's reaction there was to produce an emphatic reinstatement of his class in London when questions were being raised over his status as the undisputed world No 1. Next for Bolt is Oslo in a week's time – after a stop off in Paris to present the trophy to the winner of the men's title at the French Open – as he builds towards regaining the world crown he lost in Daegu two years ago.

For Gatlin, in particular, Blake and his other pursuers, will have offered a huge fillip. Any win over Bolt would be memorable, said Gatlin – the Jamaican has lost twice in the Diamond League over the distance in the last five years; to Tyson Gay in 2010 and to Asafa Powell in 2008. Gatlin demonstrated that Bolt 2013 can be caught, at least early-season Bolt 2013.

Just 10 weeks after undergoing a double hernia operation, Dai Greene emerged unscathed from his comeback 400m hurdles race, finishing fifth in 48.81. It was the Welshman's first race since the disappointment of finishing fourth at last year's London Olympics and he described it as a "promising" first step towards defending his world title in Moscow. Greene was third coming into the home straight before fading in a race won by world No 1 Johnny Dutch of the US.

"It was what I expected," Greene said afterwards. "I am very pleased with that after what has happened recently. Going over the last two barriers I was quite fatigued – that's where the speed endurance really tells, that's the stuff I've really missed. Considering where I'm at, that's a very promising start. It's nice to be back."

Shara Proctor finished an encouraging third in the long jump. Hannah England finished fourth in a high-class 1500m field, with Lisa Dobriskey in 10th. Phillips Idowu pulled out of the triple jump after three attempts on a low-key return.