A Carlton restaurant owner, who made a lucky escape when his pizzeria exploded in Lygon Street this morning, said the front doors had already been blasted off their hinges as he ran from the shop.

Karlos Farah, owner of Mercadante, was fumigating the restaurant's kitchen with 10 pest-bombs when the contents of the aerosol cans ignited, causing the blast about 10am.

The front of the Mercadante restaurant was blown out in the blast. Credit:Meg Rayner

Mr Farah said he believed the highly flammable fumes had been sparked by a fridge motor.

"Any normal person would think keep [pest bombs] away from flames but I didn't know [about] just having the electrical fridge on," he said.