Having started out as a conventional sprinter, Tobi Amusan took silver in the 100m hurdles at the 2014 African Youth Games. She won the African junior title in March 2015 and then, six months later, the 18-year-old Nigerian scorched to African Games gold in Brazzaville, Congo.
In 2016, she started at the University of Texas at El Paso (UTEP) and broke 13 seconds for the first time with a run of 12.83. At the NCAA Outdoor Championships, she finished second behind University of Kentucky's Jasmine Camacho-Quinn. Both women went to the Rio 2016 Olympic Games, with Camacho-Quinn representing Puerto Rico, and made semi-final exits.
At the start of 2017, Amusan clocked a career best 12.63. She bettered that at the NCAA Outdoors, running 12.57 to reverse form with Camacho-Quinn from 12 months earlier. At August's World Championships in London, she would again go out in the semi-finals.
After winning the Commonwealth Games and African titles in 2018, she retained her African Games crown in 2019. Later that year, she ran a personal best 12.48 in the semi-finals at the Doha World Championships, but missed out on a medal by just two-hundredths of a second.
At Tokyo 2020, held in 2021, finished fourth again at a major competition with her old college rival Camacho-Quinn taking gold. But that all changed a year later at the 2022 World Championships.
In the semi-finals in Eugene, Oregon, Amusan broke the world record with a time of 12.12 - eight-hundredths inside Keni Harrison's mark from 2016. In the final, she went even quicker, but an excessive wind reading saw her 12.06 ruled out for record purposes. However, she had shaken off her "almost girl" tag to become Nigeria's first track and field world champion.
Amusan retained her Commonwealth Games title later that year but was provisionally suspended in 2023 due to her missing three drug tests in a 12-month period. That ban was lifted just before the 2023 Budapest World Championships when a disciplinary tribunal cleared her of a doping violation, and she went on to finish sixth in her world title defence.
With that controversy behind her, Amusan clinched a third consecutive Diamond League title. She also completed a hat-trick of African Games triumphs in 2024 in Accra where she also anchored Nigeria to women's 4x100m relay gold. Now she is looking forward to trying to repeat her 2022 World Championships heroics at her third Olympic Games in Paris.