Olympic champion Usain Bolt's rare defeat over 100 metres in Rome on Thursday was not down to a flare-up of the hamstring injury which has hampered his start to the season.

Bolt was beaten into second place at the Diamond League meeting, 0.01 seconds behind London Games bronze medallist Justin Gatlin who won in 9.94.

Despite a good start, world record holder Bolt looked laboured and was unable to pull away from the field giving Gatlin the chance to edge a thrilling race.

However, the Jamaican appeared unconcerned by the outcome in a news conference spending much of the time shaking his head at a results sheet, and said it had nothing to do with his injury.

"It is part of life," said Bolt. "You win some you lose some. I have said that over the years, you won't win every race. The key thing is going to a major championship and showing you are number one and I am looking forward to that."

Gatlin by his standards got a slow start but was ahead at halfway and held on for victory.

Meanwhile there was a surprise defeat for Olympic champion Allyson Felix, well beaten by Ivory Coast's Murielle Ahoure in the 200m after running a poor bend.

Presented by Adam Justice