American hurdler Masai Russell has broken Nigerian sprint hurdler Tobi Amusan’s world record in the women’s 100m hurdles, clocking 12.09 seconds at the Zurich Diamond League in Switzerland.

Russell’s time, recorded on Thursday at Zurich’s Letzigrund Stadium, shaved 0.03 seconds off Amusan’s previous record of 12.12 seconds, which had stood for more than four years.

World Athletics described the Olympic champion’s performance as a flawless run, with a legal wind reading of 0.0m/s.

Amusan finished second in a season-best 12.23 seconds, while Netherlands’ European champion Nadine Visser took third in 12.34 seconds.

The result makes Russell the new world record holder and the fastest woman ever recorded in the 100m hurdles.

Russell, 26, was born on June 17, 2000, in Upper Marlboro, Maryland, and specialises in the 100m hurdles. She won Olympic gold in the event at the Paris 2024 Games and currently sits at the top of the world rankings.

Her rise to the top began during her collegiate career at the University of Kentucky, where she became an 11-time All-American. In 2023, she set the collegiate 100m hurdles record with a time of 12.36 seconds at the Texas Relays.

She had also emerged as a serious threat to Amusan’s world record earlier this year. In May, Russell clocked 12.14 seconds in Xiamen, China, moving within two hundredths of a second of the Nigerian’s mark and setting an American and Diamond League record at the time.

The breakthrough finally came in Zurich, where Russell improved her personal best by five hundredths of a second and became the first woman to officially run below Amusan’s 12.12 world record.

The significance of the performance was heightened by Amusan’s presence in the same race. The Nigerian, who had held the world record since 2022, watched as Russell claimed the mark before finishing second.

Amusan had established the previous record at the 2022 World Athletics Championships in Oregon, where she ran 12.12 seconds in the semi-final with a legal tailwind of 0.9m/s.

She later clocked 12.06 seconds in the final, but the mark was ineligible for record purposes because the +2.5m/s wind exceeded the permitted limit.

Russell’s latest achievement adds to an already outstanding 2026 season. She entered the Zurich meeting after winning the Lausanne Diamond League on August 21 in 12.27 seconds, her ninth victory of the season.

Her new 12.09-second world record now places her at the summit of an event that has been dominated by Amusan in recent years, with the American heading into the remainder of the season as the woman to beat in the 100m hurdles.