Qualification: First three in each heat.
Heat 1 - Daniel Caines of Great Britain won the all-important race for the pole after 200 meters. He was followed closely by Milton Campbell of the US and the 1997 world indoor champion, Sunday Bada of Nigeria.
Caines and Campbell continued to hold control of the race and took the first two qualifying spots with 46.43 and 46.69, respectively.
On the final back stretch, Sofiane Labidi of Tunisia made a move forward from his rear position, and then dispatched Bada on the final home straight, only to be disqualified after the event for obstruction, leaving the third qualification spot to David Canal.
Heat 2 - James Davis of the US led Jamaican Danny McFarlane and Britain's Mark Hylton off the first lap, and that was the way things stayed down the final back straight.
Felix Sanchez of the Dominican Republic tried to break into the top trio with a move with 100 meters remaining, but it was too weak and too late.
Davis held the lead coming off the final straight, but his energy was ebbing as the finish line drew near.
McFarlane and Hylton were both able to outsprint the US champion into the wire for the first two spots in 46.68 and 46.87, respectively, as Davis registered a 46.90 time.