Shura Kitata stunned Eliud Kipchoge to win the London Marathon around a sodden St James’s Park.
As many as 45,000 people are still taking part in the rearranged event by running their own 26.2-mile route.
However, Kenya’s Kipchoge missed out on a fifth title as Ethiopian Kitata was triumphant in the men’s race in a time of 2:05:41, one second ahead of Vincent Kipchumba.
Kipchoge dropped off the pace at the 22-mile mark and crossed the line in eighth place.
Jonny Mellor won the British title in 2:10:38, followed by Ben Connor.
Sir Mo Farah was also in the field, but this time acting as a pacemaker for the British athletes.
Meanwhile, Brigid Kosgei defied the rain and the gloom to defend her title in the elite women’s event.
The 26-year-old world record holder comfortably won her duel with fellow Kenyan Ruth Chepngetich, the world champion, who was eventually pipped for second by America’s Sarah Hall.
Kosgei broke for home with seven miles to go leaving Chepngetich, who had looked the stronger in the mid-stages of the race, far behind.
The pair were a minute ahead of their nearest challenger at the halfway mark, and looked on course to trouble the women’s-only world record of two hours 17 minutes and one second.
But as the rain began to fall harder the pace slowed and Kosgei eventually crossed the line in 2:18.58, almost five minutes outside her world record set in Chicago last year.
“The weather was not good so we struggled,” said Kosgei. “I struggled up to the moment I finished.
“We have not prepared well due to the pandemic. I will be prepared for good results next year.”
A tiring Chepngetich was caught by a stunning late charge from Hall, who overtook her with just a few strides remaining.
There was disappointment for the two big British hopefuls, Lily Partridge and Steph Twell, who both pulled out well before the finish.
The British title instead went to Natasha Cockram, who finished outside the Olympic qualifying mark in 2:33.19, four seconds ahead of Naomi Mitchell.
The race, originally scheduled to be run in April, was adapted to 19.7 laps of St James’s Park rather than the traditional street route, and was restricted to elite runners only, due to the coronavirus pandemic.