Mason Foster (4-7) led the bowling effort with a four wicket haul, while Kalani Snooks (2-11) and Joel Bickers (2-13) chipped in to help Northern Wairoa to the 199-run thrashing.
The other match of the round saw an 18 wicket thriller between Whangarei Boys' High School Blue and Gold.
WBHS Blue were rolled for 43 in their innings. But what normally would be a comfortable chase proved to be anything but as WBHS Gold lost regular wickets.
They ended up sneaking past WBHS Blue's total with two wickets in hand.
The last round before the finals will be tense as WBHS Gold and Kamo High, the two sides battling out for the other finals berth, face each other on Saturday.
The other match pits Onerahi Central Huanui College face WBHS Blue. Northern Wairoa have the bye.
Table:
Northern Wairoa - 12 points
Kamo High - 6 points
WBHS Gold - 3 points
OCHC - 0 points
WBHS Blue - 0 points