Kenya's Kelvin Kiptum smashed compatriot Eliud Kipchoge's course record to win the men's London Marathon in the second-fastest time ever.
The 23-year-old was just 16 seconds outside Kipchoge's world record, finishing in two hours one minute 25 seconds.
Sifan Hassan also produced a remarkable run to win the women's race.
The Dutch Olympic track champion, 30, suffered with a hip injury but battled to win on her debut at the distance.
Kiptum knocked one minute and 12 seconds off Kipchoge's previous course record to beat second-placed compatriot Geoffrey Kamworor by almost three minutes.
Britain's Mo Farah was ninth in his final London Marathon, with the 40-year-old four-time Olympic champion revealing after the race that he would finish his career at the Great North Run in September.
Hassan, who won the 5,000m and 10,000m at the Tokyo Olympics in 2021, appeared out of the women's race after dropping back early on with a hip problem, but somehow fought back.
She then produced a sprint finish to win in two hours 18 minutes 33 seconds.
Switzerland's Marcel Hug knocked 50 seconds off his own course record to win a third consecutive London Marathon men's wheelchair race - and fifth in total.
Australia's Madison de Rozario held off Manuela Schar, of Switzerland, in a sprint finish to win the women's wheelchair event for a second time.
More than 48,000 runners are taking part in the marathon, raising millions of pounds for charity, with huge crowds lining the streets of London despite damp conditions.
The event has returned to its traditional date in the calendar, in April, for the first time since 2019 after being moved during the Covid-19 pandemic.
'London has been my dream'
Hassan's rollercoaster of a race looked all but over after she fell off the leading group with just an hour gone.
"I had a problem with my hip, which made me stop. But it started to feel a little bit better," she told BBC Sport.
"And then I missed one of the drinks stations. I didn't practise that part of the race because I have been fasting [during Ramadan] and so that was quite difficult. But I needed it.
"At 20km I knew that I could kick on because I didn't feel that tired and I didn't care how I finished, I just wanted to get there."
After battling through the pain, Hassan's track speed proved telling down the Mall, as she beat Ethiopia's Alemu Megertu into second place, while Kenya's previously unbeaten Olympic champion Peres Jepchirchir was third.
"London has been my dream," added Hassan. "And now here I am, I was doubting that I could even finish. This is just amazing. I will never forget this in my whole life."
The women's field was billed as the greatest ever assembled, but Kenyan world record holder Brigid Kosgei dropped out after just three minutes, while Ethiopia's defending champion Yalemzerf Yehualaw was fifth.
Sam Harrison, 27, was the first British woman home, clocking a new personal best of 2:25:59 as she finished 11th.
It was the fifth-fastest time by a British woman in the event.
'Part of me was wanting to cry'
It was perhaps made more poignant that Farah should reveal a date for the end of his career on a day when Kiptum announced his arrival as marathon's newest world star.
Farah had already made clear that this would be his last time running the London race and he said he was close to tears on his way round.
"London has been so great to me over the years and I wanted to be here to say thank you to the crowd and the support that was just amazing," he said.
"Part of me was wanting to cry. The people were amazing, even in the rain to line the streets and that's what this is all about. It's what has kept me going for so long throughout my career."
Kiptum produced the fastest marathon debut in Valencia in December, where he finished in 2:01:53 - the third-fastest time in history.
He went faster still on the streets of London, leaving a high-class field in his wake, with Ethiopia's reigning world champion Tamirat Tola in third, three minutes and 34 seconds behind.
Emile Cairess, 25, produced a superb run to finish as the first British man home, taking sixth in 2:08:07 on his marathon debut.
It was the third-fastest marathon time by a British man - behind Farah and Steve Jones - and the second fastest by a Briton in the London race.
Four British runners finished in the top 10, with Phil Sesemann eighth and Chris Thompson 10th.
Hug a dominant force
Switzerland's Hug, 37, dominated the men's wheelchair race to finish in one hour 23 minutes 48 seconds, well ahead of the Netherlands' Jetze Plat in second, with Japan's Tomoki Suzuki third.
Britain's David Weir, 43, finished his 24th London Marathon in fifth place.
The women's race was much closer, with the four favourites making it on the Mall together before De Rozario and Schar pulled away.
De Rozario won in one hour 38 minutes 52 seconds, with defending champion Catherine Debrunner, of Switzerland, in third and the United States' Susannah Scaroni fourth.
Eden Rainbow-Cooper, 21, who was third in 2022, was the first Briton home in seventh.
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from Via PakapNews