Wearing a pair of shorts hastily borrowed from his 15-year-old brother and a T-shirt bought from a London Marathon stall, Josh Griffiths took a moment to look around in disbelief. To one side was Abel Kirui, a double world champion and Olympic silver medallist. To the other Kenenisa Bekele, widely considered the greatest distance runner of all time.

Then there was Griffiths – a self-coached student who had missed his train back to Wales and was instead hobnobbing with running royalty. “You feel like you shouldn’t really be there,” he says, with a baffled chuckle. “It was crazy.”

We meet a few days after Griffiths, 23, produced one of the shock results of recent London Marathon history when he broke clear of the club running ranks to beat every British elite athlete and unexpectedly qualify for this summer’s World Championships in the process.

His phone has not stopped ringing since he crossed the line and although he would probably admit he is not a natural orator, he is keen to savour the attention, aware this is something he never thought he would experience.

As I turn into the small cul-de-sac in rural west Wales, he is already eagerly standing in the doorway of the family home he has lived in since he was 10 years old.