The first three did their job so that Richardson, the individual 100m champion, was always in control.

Jamaica's Shericka Jackson (29), the 200m champion, had too much to do as they took silver in 41.21 while Britain claimed bronze with 41.97.

Earlier, the US men won their 4x100m relay final but the US women's 4x400 team were disqualified from the semi-final after an illegal baton change.

Noah Lyles (26) completed a glorious World Championships when he anchored the United States to victory in the World Championship 4x100 metres relay to claim a third Budapest gold medal on Saturday.

Despite their rich depth, the US had not won an Olympic final since 2000 and had just one gold from the last seven World Championships amid a series of fumbles and disqualifications.

But they were almost faultless on Saturday as Christian Coleman (27), Fred Kerley (28), Brandon Carnes (28) and Lyles won in 37.38.

Olympic champions Italy, with Tokyo individual gold medallist Lamont Marcell Jacobs (28) on the second leg, took silver with 37.62, with Jamaica finishing strongly to edge out Britain for bronze in 37.76.