"When I saw that someone had won, I turned to my flattie and said 'some lucky bastard's got the lot!'" the winner said.
"We talked about what we'd do if it was us for a bit, then I finally logged in and checked my ticket.
"All of a sudden I saw a cluster of numbers in the middle of my ticket and thought I might have been lucky enough to win Second Division. Then I saw '$5,000,000' pop up next to my ticket."
The winner couldn't believe his luck.
"I jumped up, turned to my flattie and said 'It's me! I won it!' She just stared at me blankly, so I tossed my phone at her so she could see for herself.
"We both just stood in the lounge absolutely dumbstruck."
He planned to spend some of the money on having a good Christmas.
"I'm going to make sure that this year it's really special. I won't be asking for any presents though - after all, winning $5 million with Powerball really is the best gift I could have ever received.
"All I know right now is that 2017 will be one hell of a year!"
This is the second time in five days Powerball First Division has been won by a MyLotto player, with a young Auckland woman taking home $10 million with Powerball last Saturday.
It is the 12th Powerball prize won this year.