Great Britain’s Christine Ohuruogu failed in her bid to win a third world title as she finished last in the women’s 400m behind gold medallist Allyson Felix of the United States.
It was Felix’s ninth world title, just one behind Jamaican Usain Bolt’s record of 10 gold medals at the Championships.
Felix, 29, dominated from start to finish to win in 49.26 seconds – the best time in the world this year.
Bahamian Shaunae Miller took silver with Jamaican Shericka Jackson third.
Defending champion Ohuruogu, 31, racing on the track she won Olympic gold seven years ago, faded on the home straight and finished in 50.63.
Felix, the Olympic 200-metre champion held a commanding lead by 150m and off the final bend she was clear of her nearest rival Miller, who ran a personal best.