Jemma Reekie has broken training partner Laura Muir's British indoor mile record in New York.
Reekie, who took half-a-second off her fellow Scot's 800 metres mark in Glasgow last week, ran four minutes 17.88 seconds at the Millrose Games.
Only Ethiopian great Genzebe Dibaba (4:13.31) and Romanian Doina Melinte (4:17.14) have run quicker indoor miles than 21-year-old Reekie, who took nearly a second off Muir's 4:18.75 best.
Reekie ran the first 1500m in 4:00.56, which would also have been a British record.
She rang her coach Andy Young after the race, tweeting: "I just called Andy to ask if 4.17 was a good mile time for him to tell me it was a British record. WOW."