Willie Sibbald, from Edinburgh, matched all six numbers on his Lucky Dip ticket for Saturday's Lotto rollover draw, scooping winnings of £7,084,472.
The 48-year-old broke the good news to his friend and colleague of 17 years, Rab Layden, and they both handed in their notice on Monday following a pact that they would "see each other right" if one of them ever won the lottery.
Mr Layden, 57, also from Edinburgh, was at work painting a kitchen when he received the call. The pair, who decorated houses and commercial properties, then met and told bosses they would not be returning to work.
"He phoned me at 1.45pm and said 'By the way I've got something to tell you, are you sitting down? I'm the guy that won the lottery' - and I about collapsed," Mr Layden said.
"I then met him at the yard and told the bosses at 2.40pm and retired five minutes later. Then we went for a pint."
The two friends have both played the lottery every week for years, buying two tickets each, and promised if either of them won they would make sure the other would not need to work again.
Mr Sibbald said: "We used to say 'Imagine it was us, what would you do?' But you never expect it.
"It's one of those things you say. You're sitting there eating your piece and you'd say 'Rab, imagine if we won this, you'd never need to work again.' But you never really think it's going to happen."
The pair are both dedicated followers of the Scotland national football team and are now looking forward to travelling to all the away matches.
Mr Layden said: "Obviously Willie has turned up trumps.
"The trust and the loyalty is there, there was never any doubt about it. Truth and honesty always comes to the fore."
Mr Sibbald admitted he had missed the live draw after falling asleep and only realised he was a multimillionaire later when he was watching TV and spotted the winning numbers during an advert break.
Describing the moment he realised he had won, Mr Sibbald said: "I was staying with one of my relatives and I checked the ticket and shouted to my auntie 'I've won the lottery' and we checked the ticket again and again. It was just crazy."
Mr Sibbald then had to hide the ticket from his aunt's pet dog Sandy, which likes to eat pieces of paper.
After putting down his paint brush, he now hopes to buy a Rolls-Royce - after he learns to drive.
l There was no winner of last night's £30m EuroMillions jackpot. The winning numbers are 7, 16, 19, 22, 33 and lucky stars two and five.
Millionaire Raffle: HQG351830