Josh Kerr smashed Steve Cram’s 39-year-old national record to claim victory in the mile race at the Diamond League meet in Eugene, Oregon.
The Scottish runner won a highly-anticipated showdown with Norwegian rival Jakob Ingebrigtsen thanks to a remarkable, world-leading run of 3:45.34.
Cram had held the British record since 1985 with a time of 3:46.32.
Olympic 1500m champion Ingebrigtsen, who was stunned by Kerr in that event at last year’s World Championships in Budapest, finished second, with Britons Neil Gourley and Jake Wightman in fourth and fifth respectively.
Earlier, Keely Hodgkinson produced a dominant display to win the women’s 800m. The 22-year-old clocked a world-leading time of 1:55.78, while compatriot Jemma Reekie was third – behind Kenyan Mary Moraa – in a time of 1:57.45.
Sprinter Dina Asher-Smith came third in the women’s 100m in a season’s best time of 10.98s. Compatriot Daryll Neita finished fourth in 11.00, with American Sha’Carri Richardson (10.83) claiming victory ahead of St Lucia’s Julien Alfred (10.93).
Laura Muir continued preparations for this summer’s Olympics in Paris with fourth place in the women’s 1500m in a season’s best 3:56.35.
The Tokyo 2020 silver medallist said: “I want to be in the best shape I can for August, so it’s a step towards that to run 56 (seconds) in May. It’s very promising.”
Elsewhere, Kenya’s Beatrice Chebet set a new world record of 28:54.14 to win the women’s 10,000m.