Hawke's Bay halfback Sheridan Rangihuna succeeded with seven of his attempts at goal for an 18 point haul, four penalties and three conversions.
Talented fullback Tamati Samuels was a late withdrawal from the side as his hamstring injury was still niggling him but Bay manager Blair Heasley is confident Samuels will be fit for the final.
"It was perfect summer-type conditions over here. We should have put 80 points on the Naki but our performance was patchy ... the fact we know we can improve is a good sign going into the final," Heasley added.
Fullback Nikau McGregor ran in five tries as the Hawke's Bay under-13s beat their Manawatu counterparts 43-21 at Napier's Park Island on Saturday.
After a dominant first five minutes Hawke's Bay made too many handling errors and dropped off too many tackles which allowed Manawatu to establish a 14-5 lead at half time. In the second half, Hawke's Bay committed more players at breakdown time, retained the ball better and classy backs like McGregor and centre Quevane Gurnick were able to strut their stuff.
Busy No8 Cameron Huata, openside flanker Nathan Epplett and lock Jon Joseph-Scales all had high work rates in the host pack.