American Olympic champion Masai Russell set a new women's 100m hurdles world record at the Zurich Diamond League on Thursday, clocking 12.09 seconds to surpass the 12.12-second mark set by Nigeria's Tobi Amusan at the 2022 World Athletics Championships. Amusan, who had held the record for four years, was present on the track as it fell but responded with a season-best 12.23 seconds to finish second. Russell's record-breaking run, achieved without wind assistance, also set a Diamond League and meeting record, while Amusan's strong showing signals her continued competitiveness ahead of the Diamond League Final in Brussels next month.