World and Olympic champion Emmanuel Wanyonyi set a new world's best in the men's 1 000m at the Diamond League meet in Monaco on Friday.
Wanyonyi took 0.13 seconds off the previous world best of 2min 11.96sec set by his Kenyan compatriot Noah Ngeny in Rieti, Italy, in 1999.
Patryk Sieradzki was the pacemaker at the Stade Louis II and he duly set off at an electric pace, immediately splitting the pack in the non-Olympic distance.
Sieradzki hit 400m on world record pace of 50.95sec, as planned. The second pacemaker hit
Louey Ouerrat took up the running at the bell and went through 800m in 1:45.11.
That left Wanyonyi to turn on his afterburners with 200 metres to run, Britain's Jake Wightman on his shoulder.
Wightman, the 2023 world 1 500m champion, looked like he had enough in the tank to go shoulder-to-shoulder with the Kenyan down the home straight.
But Wanyonyi showed all his class to pull away for victory in 2:11.83, the Briton clocking a personal best of 2:12.77 in second.
"This was the first time I ran the 1 000m, and directly breaking the world record makes me so happy," said Wanyonyi, immediately dismissing any talk of a tilt at the 800m world record set by fellow Kenyan David Rudisha when winning Olympic gold in London in 2012.
"I want to thank the other athletes for pushing me to my limits.
"I don't want to talk about the world record in the 800m. I first want to run fast and improve my personal best. Let me keep quiet, actions speak louder than words."
Wanyonyi added: "My next competition is in London. I have decided to not run too much this season because I want to run very fast at the end of the season."
Wightman said he had wanted to "go really, really quick and I knew Wanyonyi would be tough over 1km, but I did not know how it would be in the last 200m".
"I was nearly there. This was just a long 800 so I wanted to go through quickly and try and hang on for as long as I could.
"I wish I could have surprised Wanyonyi but it is probably the best 100m you have ever had, so it was hard."