The Scottish winners of a £57.9m (€65m) EuroMillions jackpot were initially told they did not have a winning ticket and it was ripped in half and put in the bin.
But a message on a lottery terminal in Fred and Lesley Higgins's local shop in Aberdeenshire, Scotland, told them to keep hold of the ripped ticket and call operator Camelot.
They were given the torn ticket back, went home and checked the numbers to find they did indeed match and they were the winners of the 10 July jackpot.
But even then, they misread the size of the jackpot and thought they were only £5.7m richer.
The retired couple were told that because the ticket had been torn, processing the claim would need to be investigated. A security team spoke to them about what had happened and checked CCTV footage.
Regular player Mr Higgins, 67, said: "I handed the ticket over and the young man put it through the machine, telling me it wasn't a winner. He ripped the ticket in two and threw it into the bin, as they would with all non-winning tickets.
"But this time, the terminal produced a [receipt] which said I needed to retain my ticket and call Camelot. The retailer immediately grabbed it out of the bin and handed it to me.
"The ticket had been torn in two but all the numbers were still clear, so I took it back home to make the call.
"Lesley was snoozing so I thought I would look at the website to double-check the numbers and sure enough, the first matched, then the second matched, match, match - we had them all.
"When Lesley woke, I explained we had a winning ticket and what had happened. I showed her the numbers, asked her to check and she misread them, thinking we were £5.7m richer rather than an amazing £57m.
"I felt really calm at that point - I think it was just sinking in - so I then called Camelot and explained what had happened."
Mr Higgins added: "I wasn't ever concerned that we wouldn't get the money as I knew it was an honest mistake - it just had to be looked at to make sure everything was correct."
Once the money was in their account, Mrs Higgins, 57, handed in her notice from her role as an account manager.
The couple, who have been married for 35 years, have already bought a brand new Audi cabriolet and are considering visiting India and China as well as looking at second homes in Barbados.
Camelot said: "When validating any major prize, Camelot has to ensure that the winner is the rightful ticket-holder. As the ticket was ripped in two, a range of security checks had to take place."
A spokesman added: "We are so glad to be able to pay Fred and Lesley this amazing sum. It is essential that we ensure we are paying the rightful ticket-holder, and in situations like this it can take a little time for these investigations to be completed."