The husband, who sat in the car while his wife went into Andrew Spence Pharmacy in Onekawa to check their ticket, began to question why his partner was taking so long.
"The people in the car next to me had also gone into the store and come out with a ticket, but there was no sign of my wife," he said.
"Then I saw her coming towards the car with a big smile on her face, and she handed me the claim form through the window and was laughing."
The woman, who described the moment as "surreal", said the pair celebrated with an unusual combination of rum and cheese on toast.
"I don't swear very often, but I did at that moment," she said. "When I saw how much we had won I thought 'am I really seeing this?'
"I went straight to the top shelf for the rum. But when it came to food – we couldn't really stomach a lot."
The duo said their daughter had encouraged them to check their ticket after finding out the winning ticket was sold at Andrew Spence Pharmacy – the second luckiest Lotto store in Hawke's Bay, after Unichem Stortford Lodge Pharmacy in Hastings and Napier Countdown.
"My daughter knows that I buy my tickets from the store, but I just said dream on," she said.
"So when I sent her a photo of the claim form later in the week – well, she was very excited."
The lucky pair said they will take time to reassess their future, before helping their children buy their first homes, book holidays and lock the rest away with financial help.
"I can't help but feel guilty when I buy myself something new, but I guess I won't be doing that anymore," the wife said.
The woman and her husband, who are regular Lotto players, bought two tickets for the mammoth $50m draw – one Triple Dip and one with their own numbers.
"One of my first questions was whether we won from our own numbers or the Dip ticket – turns out it was the Dip," he said.
Lotto NZ head of communications Marie Winfield said they were waiting patiently for the "elusive" Napier winner to come forward.
"It's unusual for such a big prize to go unclaimed for nearly a week – we usually hear from winners within a few days," she said.