Tobi Amusan broke the 100m hurdles world record with a stunning semi-final time of 12.12 seconds – before taking gold at the World Athletics Championships in Eugene, Oregon. The 25-year-old ran even faster in the final – but her 12.06 was ruled ineligible by an illegal tailwind.

Amusan, who had already run a new African record of 12.40 seconds in Saturday’s heats, said: “I believe in my abilities, but I was not expecting a world record at these championships. I wanted to get out and go. I did what I had to do.”

The previous record of 12.20 was set in 2016 by American Kendra Harrison. Jamaica’s Britany Anderson took silver and Puerto Rico’s Olympic champion Jasmine Camacho-Quinn got bronze. Great Britain’s Cindy Sember finished fourth in the semi-final won by Amusan, but qualified for the final with a British record of 12.50, beating sister Tiffany Porter’s 2014 mark by one-hundredth of a second.

It was one of four national records, excluding Amusan’s, run in the semi-finals, with another seven athletes equalling or breaking their personal bests. “That was a crazy race. I actually thought I was running slow. Tobi was amazing, I can’t deny,” said Sember, who went on to finish fifth in the final.