MONACO (AP) — Usain Bolt overcame a tentative start to win the 100 meters in 9.88 seconds at the Monaco Diamond League meet Friday, beating a strong field in a tuneup for next month’s world championships.

The Jamaican improved his personal best this season by 0.03 seconds, but was well short of his world mark of 9.58 seconds.

Nesta Carter of Jamaica was second in 9.90 seconds and Michael Rodgers of the U.S. was third in 9.96. They were followed by Michael Frater of Jamaica (10.01) and European champion Christophe Lemaitre of France (10.03).

Bolt got off to a poor start and battled all the way on a fast track and with a slight tail wind. The triple Olympic champion failed to beat the Herculis meet record of 9.82 after surging ahead in the last 20 meters.

“Nesta Carter, Michael Frater are very good starters, better starters than me,” Bolt said. “But the last 60 (meters) are the best part of my race, so I was never really worried. Overall it was good.”

Bolt, who competed for the first time on the Stade Louis II track, is unbeaten this season and said winning races, even by small margins, is the most important thing ahead of the worlds.

“For me it’s always key to keep winning,” he said. “And I’m getting better. My last 60 meters have improved dramatically. I need to work on my reaction time, but I’ve been doing great in training, so I’m just focusing and I feel ready.”

The worlds start Aug. 27 in Daegu, South Korea. Bolt’s last race before the championships will be the 200 at Stockholm next week.

Bolt was hampered by injuries last season. He has said that he won’t lower his 100-meter world record this year and is concentrating on defending his sprint titles in Daegu.

“My aim this season is to run 9.7, maybe 9.6,” he said. “For me, this year it’s about building myself and go into the Olympic season fit and ready. London is the key.”

Copyright 2011 The Associated Press.