He said that moments after getting into the ute, parked in a lane at the back of the store, there had been an "incredible blast noise, like a bomb going off".
He said he was lucky to be alive after the explosion.
Mrs Bayliss said, "Don's hair caught fire and everywhere not covered by clothing or exposed was burnt. He is also minus his eyelashes and eyebrows and lots of his hair."
She said her husband had not panicked and had got himself out of his vehicle, but got back in to try to move it to reduce the risk of damage to his store and nearby buildings. However, he had had to get back out because the flames were too fierce.
He then ran back into his store to get a fire extinguisher to try to put the blaze out.
People who heard the blast were quick to help with damp towels and cold water until an ambulance and fire crews arrived.
Mrs Bayliss said her husband's burns had been described as moderate but doctors were still assessing the degree of his burns and deciding on whether he needed skin grafts.
She said she wanted to thank all those who came to her husband's aid. "Don's a bit of a mess at the moment. "
The exact cause of the fire was still being investigated but Mrs Bayliss said no lighter or cigarettes were involved in the explosion.
Waihi Beach Chief Fire Officer Ian Smith said petrol vapour could build up and explosions were common. "It is always a good idea to store fuel in a cool place, out of the sun."
