The 35-year-old had expressed her belief last week that Radcliffe’s mark of 2:17:42 was achievable and sought to justify the claim by setting off at a blistering early tempo.

Having pulled away from her main rivals in the opening kilometres, Keitany found herself well under the pace required to beat Radcliffe’s absolute record of 2:15:25, a time he Briton set with male pacemakers and often described as "Beamonesque".

The 2011 and 2012 winner went under the halfway mark in a time of 1:06:54, over a minute faster than Radcliffe managed when she achieved her best mark here in 2003. 

Keitany’s early efforts increasingly appeared to be taking their toll as she began the second-half of the race, with Radcliffe’s absolute best moving out of reach.

The slowing pace offered a chance for second place Tirunesh Dibaba to close on the leader but the Ethiopian’s hopes of catching Keitany were ended when she suffered stomach problems, briefly causing her to draw to a halt.

Keitany, meanwhile, powered as as she ran down the finishing straight with a women’s only best in sight, achieving the feat in 2:17:01.

Dibaba recovered to end in second place in 2:17:56, with fellow Ethiopian Aselefech Mergia ending 5:12 behind in third place.

“We had planned to run 2:18 so it was a great day for me to run so fast,” said Keitany. 

“I thought I would run 2:17:59 or something, so to run 2:17:01 is amazing.

“My body felt fit enough and I have trained well and I tried to push all the time. 

"I’m very happy with the finish time.”

The men’s title was claimed by Kenya’s Daniel Wanjiru, though he was forced to hold off a late challenge by Kenenisa Bekele.

The Ethiopian, a triple Olympic champion on the track and the world 5,000 and 10,000 metres record holder, had appeared to have fallen out of contention for victory.

It followed him being dropped early on by the lead group containing Kenya’s Bedan Karoki and Abel Kirui, Ethiopia’s Olympic silver medallist Feyisa Lilesa, Ghirmay Ghebreslassie and Wanjiru.

Wanjiru pulled clear but was soon look over his shoulder to see a closing Bekele, who had come through the field after his odds with one British bookmaker having lengthened to 500-1 following his mid-race crisis.

Bekele continued to close in on the leader as the finish approached but Wanjiru did enough to secure the victory in 2:05:48.

“I’m really happy as it’s my biggest win at my first attempt at a World Marathon Majors race,” said Wanjiru

“I’ve been preparing to win this race since Christmas so I’m very grateful that I achieved my goal.”

Having finished third last year, Bekele ended nine seconds down to end as the runner-up.

The top three was completed by Karoki, who finished in 2:07:41.

The men’s elite and mass start races were started by Prince Harry and The Duke and Duchess of Cambridge.

A record 40,000 people are expected to have taken to the start-line for the 26.2 mile race.

This year’s London Marathon has seen the organisers support the Heads Together charity to raise awareness around mental health.