Jemma Reekie's 800m winning streak ended with a fourth-place finish at the Gala dei Castelli International meet in Bellinzona, Switzerland.
The 22-year-old Scot - who was unbeaten over the distance in 2020, with three outdoor wins last month and two indoor successes in February - ran 1:58.87.
But she was outside the top three, with Norway's Hedda Hynne winning in a world-leading outdoor time of 1:58.12.
Jake Wightman, meanwhile, took third in the 800m in Zagreb.
The Scot clocked 1:44.85 at the Hanzekovic Memorial to complete a British 1-2-3 behind English pair Daniel Rowden and Elliot Giles.