The men's 400 metres at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha on 1, 2 and 4 October 2019.

Van Niekerk couldn't compete because he injured his knee in a celebrity rugby game and James was battling Graves' disease, the same ailment that affected Gail Devers.

James held that lead until midway through the final turn when he began to fade back as Gardiner was emerging slightly ahead.

Coming onto the home straight, Gardiner held a 2 metre lead over James and Kerley, with Cedenio just slightly behind them.

From far back, Zambrano was in another gear, speeding past Cedenio, James and a metre before the line, Kerley.