Cellar-dwellers Hikurangi provided the upset of the round when they beat Western Sharks 29-27.
Meanwhile, the top two sides had comfortable wins to give them confidence going into the playoffs.
OBM thumped Mid Western 65-15 at home and Mid Northern beat Waipu 38-17, a result they'll want to replicate next week.
Meanwhile, the Bay of Islands and Mangonui Senior competitions had their semifinals.
In the Bay of Islands division, Moerewa and Kerikeri will contest the final.
Moerewa beat Kawakawa 48-8, while Kerikeri racked up a half-century as they demolished Ohaewai 55-17.
Other games saw Kaeo pip Okaihau 17-16 and Kaikohe take down Otiria 23-21.
The Mangonui competition featured a semifinal upset of sorts.
Te Rarawa, who finished the regular season third, defeated second-placed Eastern 32-17.
They had defeated them earlier in the season.
The other semifinal saw Awanui thump Panguru 59-7.
