It was Cameron Hellier who converted for Maungakaramea late in the third quarter which set up an exciting final period of the Friday night match.
Boys' High continued with their gameplan and showed premier level skill and pace to keep the defending champions on their toes.
Maungakaramea held their nerve in the last quarter and took their chance when Brent Woolhouse slotted one home from the top of the circle with two minutes left on the clock.
Maungakaramea player/coach Sam Webb said they were tenacious enough to get the win.
"We showed good grit to hang in there and we knew that if we just kept doing the simple stuff we'd get the chances, it just took along time to come," he said.
In the other premier men's match on Saturday, Springfield took a 4-1 win over Bream Bay while Mangapai had the bye.
In the premier women's grade, Old Girls beat Mangapai 7-0 while Whangarei Girls' High School beat Hikurangi 3-0 and Springfield beat Maungakaramea 3-1.