Justin Gatlin beat Usain Bolt by one-hundredth of a second to win the 100 meters at the Golden Gala meet.
Justin Gatlin who has won all five of his 100-meter races this year might become a serious threat to Bolt at the world championships in Moscow in August.
Justin Gatlin was the reigning Olympic champion when he tested positive, having won the 100 at the 2004 Athens Games.
Usain Bolt will next run the 200 in Oslo, Norway, next week before he returns home for the Jamaican championships. Gatlin has the U.S. trials this month.