Josh Kerr surpassed Steve Cram's 1500m mark at under-23 level at the Brooks PR Invitational in Seattle.
Edinburgh's Kerr won in three minutes 33.60 seconds - 0.06 seconds faster than the time set by Cram.
And the 21-year-old is now second in Scotland's all-time list for 1500m, behind Chris O'Hare.
Eilish McColgan also set a new personal best of 4:00.97 in Morocco, which was quicker than her mother Liz's best time over 1500m.