An electrician who won more than $20million in a Powerball jackpot has given half of his winnings away less than a week after his life-changing win.

The man in his 50s bought the ticket from New Zealand's Hornby Lotto Mall, in Canterbury, but delayed checking it after hearing the store sold a winner so he could continue 'dreaming for a while'.

When he finally checked it mid-week, one of his first reactions on receiving the jaw dropping news was to start divvying it out to family, to keep him on an 'even keel',' New Zealand Herald reports.

The man in his 50s who won more than $20million in a Powerball jackpot has given half of his winnings away less than a week after his life-changing win (stock photo used)

The Christchurch winner described feeling an overwhelming sense of relief when the 'Lotto lady' handed him the paper with $20.2 million written on it.

'You think you know how you're going to react when you get news like that, but to be honest all I felt was this huge sense of relief.

'My first thought was 'yay, I can retire now'.'

The gobsmacked sparkie went straight to his partner's workplace to present the news, where they shared 'a few tears and a couple hugs'.

'We had to hold it together as she had to go back to work. I don't think she got much done that day,' he said.

The Christchurch winner described feeling an overwhelming sense of relief when the 'Lotto lady' handed him the paper with $20.2 million written on it (stock photo used)

Later, the couple sat down for a drink and started calling family to break the exciting news and tell them about the money they'd be handing over.

'Family is the most important thing and we are so excited to be able to share our luck with the people we love most – and know that it's not just our life that has changed.'

He said giving out half the money would help save him from 'going crazy' with his winnings.

A portion of the money is set to go towards a holiday for both his families next year.