Five of the six 400m heats were won in under 45 seconds, with South Africa’s Olympic champion and world record holder Wayde van Niekerk strolling the other in 45.27.
His main rival for gold, Botswana’s Isaac Makwala, was the fastest qualifier for Sunday’s semi-finals in a rapid 44.55.
Ireland’s Brian Gregan also made it through.
Asha Philip clocked a season’s best 11.14 to reach the 100m semis, along with fellow Britons Daryll Neita (11.15) and Desiree Henry (11.32), the latter being one of the young athletes who lit the Olympic flame at London 2012.
Elliot Giles, Guy Learmonth and Kyle Langford all made it through the heats of the 800m, but Ireland’s Mark English crashed out.