Josh Griffiths' life will be changed after his shock performance in the London Marathon, according to his former coach James Thie.
Griffiths, 23, running his first marathon, finished 13th and was the first British runner across the line to qualify the World Championships.
Thie, who coached Griffiths for four years, praised the Swansea Harriers runner.
"He's really strong mentally in terms of staying focussed," said Thie.
Thie, who represented Wales at the 2006 and 2010 Commonwealth Games, said he had high hopes for Griffiths who now coaches himself.
"If you can go out there on your own on a wet windy day and get the training done then when you stand on the start line of a race you are on your own," he said.
"If you're used to that process and not reliant on other people there are benefits to being self-coached.
"I've got a feeling his life's going to change in the running world.
"He took an opportunity on Sunday. He performed out of his socks and it's a fairytale performance, but he worked so hard it's a justified performance."
Griffiths' finishing time of two hours 14 minutes 49 seconds in London means he has also qualified to run at next year's Commonwealth Games in Australia's Gold Coast.
And Thie believes Griffiths will not be heading down under just to make up the numbers.
"They still have to go through the selection process, there's no absolute guarantee, but I think barring disaster he's on that plane to the Gold Coast," he added.
"It might be a big ask, he's only 23 now,
"You'd think he'd be a real medal shot at 28 but with the progression and the improvement curve he's on, if you're a betting man you might put an outside bet on Josh Griffiths getting close to that podium."