The win was made up of $4 million from Powerball First Division and $333,333 from Lotto First Division.
The woman, who wishes to remain anonymous, tuned in to watch the live Saturday Lotto draw with her husband after she was gifted a ticket by a family member.
They wrote the winning numbers at the top of the ticket then checked to see how they had fared.
"She said, ‘I think we’ve got three numbers, have a look’," said the man.
"I said to her, ‘we haven’t got three numbers, we’ve got six - we’ve won Lotto, and we’ve got Powerball too’."
The couple said they got no sleep that night and were still "in fairyland" as they tried to make sense of their new financial position.
"It’s just mind-boggling," the woman said.
She said they planned to put the bulk of the money into a savings account while they decided what to do with it.
However, they will be using a portion of the money straight away to treat their children and grandchildren.
They also have a treat in mind for themselves.
"We’re going to look at replacing our car. We probably won’t buy a new one, but it will be an upgrade," the woman said.
The couple claimed the prize yesterday at the store where the ticket had been purchased – Whitcoulls George St in Dunedin.
Saturday night’s other big prize also went to a player in the South.
The special $1 million prize that was part of Lotto NZ’s "biggest Christmas ever" promotion was won by a player who purchased his ticket at Plaza Supervalue in Invercargill.
Another 100 prizes of $50,000 were won by players from across New Zealand as part of the promotion.
