The London Marathon’s organisers have hailed the “greatest day” in the event’s 45-year history after huge crowds watched Sabastian Sawe become the first man to shatter the two-hour barrier in an official race, and a world record tally of more than 60,000 runners started the event.

By 6.30pm on Sunday evening, organisers were also hopeful of breaking the record number of 59,226 finishers, set by the New York Marathon last year, although they said it could go right down to the deadline of 11:59pm.

Hugh Brasher, the race director, said that an estimated 800,000 supporters had watched an epic men’s race, in which Sawe and the Ethiopian Yomif Kejelcha had both run under two hours.

Meanwhile, the Ethiopian Tigst Assefa set a women’s-only world record, for races involving only female pace setters, although it was five minutes behind the outright women’s world record.

“It is, without doubt, the greatest day in London Marathon history,” said Brasher. “You work for years and years and years and then sometimes the gods make it happen.

“We have a women’s-only world record, two men under two hours, a record number of starters and a hopefully record number of finishers. And I’m sure there will be a record number of people raising money for charity. It was last year, where we raised £87m. So yes, it’s the greatest day in marathon history.”

Brasher, whose father Chris paced Sir Roger Bannister to his famous sub-four minute mile in 1954, said that Sawe’s time of one hour, 59 minutes and 30 seconds deserved to be seen in the same light.

“The sub-four mile was in Britain,” he said. “Sub two hours for the marathon was in Britain. These are historic feats. People said that Sir Roger Bannister’s mile was the greatest sporting moment of the 20th century. Is this the greatest sporting moment of the 21st century? I don’t know, but it was just brilliant.”

Brasher’s message was echoed by the former women’s record holder Paula Radcliffe, who said that the breaking of the two-hour barrier was an historic moment.

“An absolutely phenomenal race. What can you say?” she said. “To have waited how long and now two men have gone underneath two hours. It’s like waiting for a bus.

“It will reverberate around the world. The goalposts literally just moved for marathon running and where you benchmark yourself as being world-class. It has been done.”

Afterwards Sawe revealed he had been fueled by a breakfast of two slices of bread and honey and a cup of tea. And he also paid tribute to the crowds who willed him home.

“I would like to thank the crowds for cheering us,” he said.”They help a lot because if it was not for them you do not feel you are so loved. I think they help us a lot, I think you feel so happy and strong and pushing and that’s why I can say … what comes today is not for me alone, but for all of us today in London.”

There were plenty of other magic moments during a day where London celebrated the best of the capital and the best of humanity. They included Georgios Petroulakis from Greece proposing to his future wife Ismini Sermea Marathaki just after they finished – having run 26.2 miles carrying an engagement ring.

But there was less joy for Eilish McColgan despite being the leading British woman after coming seventh in 2:24.51– after her foot became drenched in blood owing to a blister.

“Not long after halfway, I had a really, really bad blister in my foot,” she explained. “It sounds strange saying it, but the only way I can say it is I felt like my foot just exploded. I just had this massive tear and I thought, what the hell is that? It was obviously pretty sore, but for it to happen quite early on, it panicked me a little bit.

“I had to go to see the doctor after the race, I just couldn’t put any pressure through my foot. And it was just totally covered in blood.

Plenty of celebrities also ran the race, including the Olympian Laura Kenny, who finished in 3:45:05. While Daddy Pig, who was running in aid of the National Deaf Children’s Society, finished in 5:51:53.

Officials at the Guinness book of world records were also busy as 36 records were set across the day, including James Dowsett, who set the time for the fastest marathon dressed as a knight after running 4:21:10

However Gill Punt, who had hoped to set the fastest marathon in a polar bear suit, was unable to do so on the day. “It was a phenomenal atmosphere,” said Gill, who has now raised over £2m for charity. “The screaming and support got me through although I was questioning my choice of a furry costume.”