Sabastian Sawe of Kenya won the London Marathon for his biggest career victory while Tigst Assefa shattered the women's-only world record.
Sawe pulled away from a leading group of nine runners about 90 minutes into the race and finished in two hours, two minutes and 27 seconds.
The 29-year-old made his move when his rivals slowed down at a drinks station - opting not to take any water despite warm temperatures.
Jacob Kiplimo, the half marathon world record holder who was making his full marathon debut, was the only runner able to give chase but could never get close to erasing the gap. The Ugandan finished about 70 seconds back in second place.
In the women's race, Assefa of Ethiopia secured her first London Marathon title after pulling away from Joyciline Jepkosgei.
Assefa finished in a time of two hours, 15 minutes and 50 seconds, the fastest ever in a women's-only marathon - but 25 seconds slower than the course record set by Paula Radcliffe in 2003 when it was a mixed race.
Assefa finished second both in London and at the Paris Olympics last year but adds this title to two Berlin Marathon wins.
Unlike in Paris, she made sure there would be no sprint finish this time as she left Jepkosgei behind with a few kilometres left and ran alone along the River Thames and through central London to the finish in front of Buckingham Palace.
Jepkosgei, the 2021 London winner, was almost three minutes back while Olympic champion Sifan Hassan was third.
Eilish McColgan, the 10,000m gold medallist at the 2022 Commonwealth Games, was eighth in her belated debut marathon in a Scottish record time of two hours, 24 minutes and 25 seconds.
And she was not the only British woman in the top 10, which also included ninth-placed Rose Harvey, but her compatriot Charlotte Purdue could not finish after pulling up with a calf issue.
It was a Swiss double in the wheelchair events, with Marcel Hug racing to his sixth London marathon title in one hour, 25 minutes and 25 seconds and Catherine Debrunner winning her third women's title in four years in one hour, 34 minutes and 18 seconds, missing her own world record by two seconds.
A world record 56,000 runners were expected to participate in the 42.195-kilometre race that started at Greenwich Park, snaked along the River Thames before finishing on The Mall.
Alex Yee endured more "dark moments" on his London Marathon debut than during his Olympic triathlon-winning turn in Paris but still declared it an experience of a lifetime.
The 27-year-old Londoner crossed the finish in two hours, 11 minutes and eight seconds, good enough for 14th place in his first attempt at the distance.
"It was seriously tough," said Yee, "but probably one of the best moments in my life. Just the feeling of everyone, that experience, I can't really put into words.
"The experience of running into London, the crowds. I expected them to be good, but that was a whole other level. I'm just immensely proud."
Yee was the second-fastest British man behind Mahamed Mahamed, last year's fourth-place finisher in London, who was ninth overall.
The triathlete pulled off an incredible late comeback last summer in Paris to claim gold but felt his maiden marathon was an entirely different challenge.
He said: "Definitely a lot more dark moments, I'd say, more than Paris, today. Once I got to 32, 33k there's a lot of pain there. My legs are cramping and I just had to keep fighting through that. And yeah, (I'm) pretty proud to get to the finish line."
