Peake carded a final round of five-under 66 to finish at 23 under, a shot clear of fellow Australian Jack Thompson, South African Ian Snyman and Kazuki Higa from Japan.
And he did it the hard way, nervelessly rolling in an eight-foot putt on the final hole to clinch the victory before raising his arms in triumph.
The 31-year-old picked up $A302,000 for the tournament win and a guaranteed start in the 2025 British Open at Royal Portrush.
Remarkably, Peake was bogey-free through his final 55 holes, despite only laying eyes on the two courses at Millbrook Resort for the first time in the practice round on Wednesday.
Even more extraordinary is Peake's back story.
As a junior prodigy he once teamed with Cameron Smith to win the boys' division of the Trans Tasman trophy in 2010 as 17-year-olds.
But shortly after turning pro he lost his way.
In 2014, Peake received a five-year prison sentence for assault.
With the aid of renowned coach Ritchie Smith and others, Peake then turned his life around without ever hiding from his chequered past.
He received a full card on the Australasian Tour for the first time in 2024-25, and this was his first tournament victory as a professional.
Peake only arrived in Queenstown 36 hours before the tournament began after a hold-up in receiving a special direction order to travel to New Zealand because he is ineligible for a regular visa.
Overnight leader Guntaek Koh from South Korea unravelled on the final day.
After starting the fourth round with a four-shot lead, Koh was overtaken shortly after the turn on Sunday and eventually signed for a two-over 73.
He was the only player in the top 38 to shoot over par on the final day.