Shortly after Sydney McLaughlin had shattered her own world 400m hurdles record in the performance of these championships – in fact most championships – she was presented with her gold medal and a $100,000 (£83,000) bonus by the World Athletics president, Sebastian Coe. “It’s the best 100 grand I’ve spent today,” he said. Like everyone else in Eugene, Coe was enthralled after a spectacular performance by the 22-year-old American, who has set world records at every age category since she was 14 and shows no signs of stopping. The Olympic champion’s latest victory, in an extraordinary 50.68sec, was her best yet. Not only did it slash 0.73 seconds off her previous mark set on Hayward Field last month, it also made her the first woman to run under 51 seconds in the event.