Amid the most remarkable scenes at the 23rd fence, where horses were falling, unseating, being brought down, hampered or refusing, came the obscure colours of Johnny Buckingham and 100-1 outsider Foinavon, weaving through the melee and safely over the obstacle to take a lead they would never relinquish.

Amid all the confusion, one man remained cool.

The late Micheál O’Hehir, the renowned sports commentator, kept his wits while horses ducked left, right, and anywhere else they could.

The rank outsider emerged as the sole participant unhindered by the calamity at the fence which would later be called after him.

“With all this mayhem, Foinavon has gone off on his own,” O’Hehir said in commentary for the BBC. “He’s about 50…100 yards in front of everything else. They’re all pulling up, having a look to see what’s happening at the fence.”

Two fences later the race had settled down a little, and Foinavon was still in command, as O’Hehir relayed: “The mess is almost over now. They’re coming to Valentine’s (Brook), and when I say ‘they’re coming’ I mean it’s Foinavon who’s coming. He is roughly 200 yards in front of everything else.”

Micheal’s son, Peter, also a greatly respected racing commentator, recalls his father telling him how he managed to spot the rank outsider so seamlessly: “He had permission to go into the jockeys’ room and he spotted Johnny Buckingham standing waiting to go into the toilet and he said to him: ‘What are you riding?’

“My father said to him that he remembered the horse had run in different colours in Cheltenham, but Johnny told him there was a change of owner — which meant a change of colours. It was a case of being in the right place at the right time the fact that he spotted the change of colours and asked the question. It meant he was ready for it when it did pop up.”

At that time, the maximum field was not restricted to 40, and just a few fences prior to the infamous pile-up, one of O’Hehir’s co-commentators had offered that there were “an awful lot” of horses still going, making it all the more remarkable that O’Hehir picked up the one horse getting over the fence without incident.

“There was no hesitation — that’s what struck me,” added Peter. “I was only eight at the time, but when I listened back to the race, the flow of my father’s commentary never stopped. There was no hesitation, no having to consult his card. In those days, there was no monitor in front of him. He was in his position up a scaffold in a little box covering that area from the fence before Becher’s until they jumped the Canal Turn.

“It was a case that they came at you, they came around you, and then they went away from you and that was it.

“He wasn’t sitting down in a box with five or six monitors all showing different angles, he had his binoculars in his hand, and saw them coming and saw them passing.

“It was smallest fence on the course then and it still is. They now call it the Foinavon Fence, and it certainly earned its place alongside Valentine’s, Becher’s and all the others.”