Timothy Cheruiyot stunned World 1,500m champion Asbel Kiprop for the second time, storming to victory in Stockholm with a world lead time of 3 minutes and 30.77 seconds on Sunday.
Alsadik Mikhou of Bahrain, who boasted of the world lead time of 3:31.34 going into the Swedish capital, came in second in 3:31.49 as Ethiopian Aman Wote followed in 3:31.63 as Kiprop finished in fourth place in 3:33.17
"I am very happy. The race went to plan - I tried to go at 300m. I go back to Kenya now and prepare for the World Champs trials," said Cheruiyot, who had beaten Kiprop to third place at the National Championships the previous weekend.
"I will be really happy if I can make it to London. This was good preparation for this," said Cheruiyot after recording his second Diamond League victory after Rabat last year.
The World Championship Trials are set for Friday and Saturday.