Rome: Six-time Olympic champion Usain Bolt said he will review the key ingredients missing from his race after being pipped to victory in his first 100 metre outing in Europe this season by American rival Justin Gatlin.
Gatlin came into the Rome Golden Gala expected to challenge the world record holder (9.58sec) on the back of two wins in the opening two legs of the Diamond League in Doha and in Eugene.
Bolt, meanwhile, was making his first appearance on the continent since his recent recovery from a hamstring injury.
The Jamaican surprised himself with a strong start but soon had trouble finding the required rhythm and later admitted his traditionally strong finish was absent.
Bolt, who will next compete in Oslo at the Bislett Games before returning to Jamaica on June 14, said he felt no twinge from his hamstring during the race but felt "a little sore" afterwards.
But he admits he has work to do ahead of the world championships in Moscow later this summer.
"I got a great start. I think the fact that I did threw me off a little," said the Jamaican. "Normally the last 50 (metres) is the best part of my race but it wasn't there.
"But I'm not worried. I wanted to find out where I was at here and now I will go home and look at the tape, see where I went wrong and come out and do better next time."
Gatlin's weaker start did not stop him clinching the win with a dipped finish in a time of 9.94, his third win in the Diamond League this season.
But the 2004 Olympic champion, who once served a four-year ban for doping, admitted his technique is also a work in progress.
"Last season I was a really good starter, this year, it's been a little slower," said the American. "I'm trying to get that back and get the middle of my race stronger.
"I just want to stay healthy. It's a long season ahead."
Olympic champion Allyson Felix settled for second in the women's 200m where Murielle Ahoure of Ivory Coast clocked a new national record on her way to the win.
The African made the most of the absence of Jamaicans Veronica Campbell-Brown, Shelly-Ann Fraser-Pryce, the Olympic silver medallist in London, and Sherone Simpson to clock a time of 22.36.
"I'm very excited and the national record is a big bonus for me," said Ahoure.
Felix finished second in 22.64, and admits her focus is on sealing her place in the USA team.
"I'm taking a different approach this year, taking more time off, so I was a little off," admitted the American.
"I'm trying to make the (US) team, run the 100 and 200 (in Moscow). I'll stay patient. It's what happens down the season that counts."
Americans topped the podium in a number of key events with Lashawn Merritt winning the men's 400m ahead of Saudi Arabia's Youssef Ahmed Masrahi.
Merritt later declared: "I would say I'm the favourite for the world championships if nobody else will say so."
Dawn Harper-Nelson won the women's 100m hurdles ahead of compatriot Lolo Jones, while Johnny Dutch literally threw himself over the line to clinch the men's 400m hurdles and Olympic champion Christian Taylor won the triple jump with a leap of 17.08.
All eyes were on Croatia's former Olympic champion Blanka Vlasic and Russia's reigning world and Olympic champion Anna Chicherova as the pair duelled for the first time in two years.
But Vlasic, returning to competition after a 20-month absence due to injury, ultimately had to settle for third as Chicherova and compatriot Svetlana Shkolina shared victory after efforts of 1.98 m.
Vlasic's best jump was 1.95 and she said: "I'm satisfied with my performance, I've improved my season's best and it's another stepping stone. I'm happy to be back."
Ethiopia's Yenew Alamirew powered down the home straight to win the men's 5000m ahead of teenaged compatriot Hagos Gebrhiwet in a time of 12min 54.95sec, slashing 10secs off the best time of the year so far.
France's Olympic champion Renaud Lavillenie, meanwhile, had to settle for second in the men's pole vault after his leap of 5.86 m was bettered by German rival Raphael Holzdeppe (5.91).