With 43.88 seconds, Kirani James was fastest qualifier in the men’s 400m semi-finals. Showing a return to the kind of form that brought him the 2012 Olympic title, the Grenada athlete, who is now aged 28, beat Anthony Zambrano in his semi – the Colombian running 43.98 seconds.

They were the only runners to break 44 seconds but world champion Steven Gardiner looked relaxed as he cruised to victory in his semi in 44.14. The Bahamas athlete was casually attired in a t-shirt and he beat a stacked field that included runner-up Michael Norman of the United States [44.52] and Isaac Makwala of Botswana [44.59].

Olympic champion and world record-holder Wayde van Niekerk was also Gardiner’s race but was straining to stay in touch with the leaders entering the final straight and he wound up fifth in 45.14, which means the South African won’t run in Thursday night’s final.

Michael Cherry of the United States was the other heat winner with 44.44 from Christopher Taylor of Jamaica, who ran 44.92 seconds.