Murupara's only defeat was a last-minute 14-12 loss against Saturday's opposition Edgecumbe in round five.
They won a home semifinal against Matata 31-22 to secure the home final against Edgecumbe.
Club president Charlie Teddy said everyone at the club was "on cloud nine" after the final.
"It was a really good final, it was hard fought and really tight, even though the score belies it.
"Both teams wanted it really bad, I think we were just a bit more organised in the backs.
"We've got 12 or so guys who are under 21 years old, it's quite a young team - the young guys really thrived with the experience.
"I'm really proud of how they played all year actually, their age doesn't reflect their maturity in terms of the game," Teddy said.
He said the win lifted the spirits of everyone in the Murupara community.
"Murupara is not the powerhouse that it was in its heyday, with job losses and what-not, but the field was absolutely packed with supporters.
"Edgecumbe came over with heaps of supporters as well, I don't think there was anyone left in Edgecumbe actually.
"We all know each other so there was a bit of light-hearted banter - it was a good day.
"We know the people of Edgecumbe have had a rough time lately and that was in the back of our minds."
Teddy said the club was in no doubt that the step up to Division 1 next season would be a challenging one but they were looking forward to it.
"It will be a good challenge, the boys went from strength to strength this season so you never know.
"I'd like to thank the whole community for their support this season, they have been second to none, and the volunteers who have worked bloody hard in the background all year."
