Kids were asked to sell their special slice of New Zealand to the judges and it was only natural for Mac to choose his own backyard.
Mac said his number one thing to do in Rotorua was to ride on the luge as he liked to go "really fast" and had even been down the intermediate track.
But the usually confident and bubbly boy was shy and had bright red cheeks when he was surprised with the announcement he had won, Karl said.
A special assembly was held at Mac's school, Lynmore Primary, and the Fair Go film crew showed up to surprise the creative youngster with the news.
Mac's mum and dad also went to the assembly when they were told Mac would be receiving a reading award.
"We had absolutely no idea," Mac's mum Kirsty said.
And neither did Mac but he came around when he was given the award and got to choose some friends to help open the box of prizes.
Mac's winning ad won Lynmore Primary School about $10,000 worth of prizes including an interactive learning suite, new cameras and camera gear and a cash prize of $2000.
The Rotorua family have had to keep the win a secret up until the awards were aired last night but were excited to finally see Mac's ad played on national television.