DOHA. Justin Gatlin and Mike Rodgers have warned their Jamaican rivals Usain Bolt and Yohan Blake that they intend to win a sprinting "dogfight” after securing a one-two in the 100m at the Diamond League opener in Doha.Gatlin, the American banned from athletics for four years after testing positive for steroids in 2006, clocked an impressive time of 9.97sec to win in the desert heat with his compatriot Rodgers a close second in 9.99sec. Bolt ran 10.09 in his season-opener at the Cayman Invitational earlier in the week. Blake missed the meeting here due to injury.Gatlin, who picked up the bronze medal at last year’s Olympics behind the Jamaican pair, is confident that the Americans can challenge for gold at the World Championships in Moscow in August. "I don’t turn up to races trying to be second and third, I train to go out there and run fast and be dominant in the race,” he said. "You want a mixture of great athletes, you want to come to an event where you really don’t know who’s going to win. You want to go out there and have a really good dogfight. You’ve got to let him [Bolt] do what he does and I’ll do what I do. When we meet each other, may the best man win.”Earlier in the evening the Olympic 800m champion, David Rudisha, eased to victory in a time of 1min 43.87sec.