American Justin Gatlin nipped Jamaica's Asafa Powell at the line to win the 100 meters in a time of 9.87 seconds at the season-opening Diamond League meet on Friday.
Powell got off to the faster start but Gatlin pulled even and managed to get his head in front as they crossed the line.
''This is fastest I ever opened up my career,'' said Gatlin, who dedicated the win to son Jace on his second birthday.
American Allyson Felix won the 100 with a meet record of 10.92, edging her Jamaican rival and reigning world 200 champion Veronica Campbell-Brown by 0.02 seconds
Gatlin tied Powell's world record in Doha six years ago, but the result was erased when he was caught doping a few weeks later. Gatlin tested positive for excessive levels of testosterone, which led to a four-year ban.
Gatlin and Powell are gearing up for the London Games. Olympic champion Usain Bolt skipped the meet, along with Tyson Gay of the United States, who is recovering from injury.
''I just showed I have a lot ...