$22.3 million Lotto winner found out he won and went to bed

A man in his 20s who won the whopping $22.3 million Powerball prize plans to set himself up for the future.

The winner, who lives in central Otago, bought the ticket on a whim on MyLotto just before the draw on Wednesday night.

The prize is the largest ever won on MyLotto and in the South Island and the largest prize won so far this year across the country.

The man says he was hanging out with his mate after work when he thought he should check his ticket, he says. 

"I said, 'Mate  I think I've won Powerball...is this real?'" the winner said.

"Mum and Dad didn't believe me  it's the kind of thing I'd pull, so they chalked it up to a joke. The whole thing felt a little too good to be true, so I just put my phone down and went to bed," the winner said.

With the reality of his big win kicking in, the young man is looking forward to planning his future.

"I want to buy a house with some land and will probably get a new car. Other than that, I want to set myself up for the future."

"This prize is an unbelievable opportunity and I am going to make the most it," he said.