As top qualifier for the final, WHS were the clear favourites, having defeated Cullinane twice, although the second match was quite tight.
That tag seemed justified when Cullinane lost their captain to a leg injury inside the first two minutes, and were trapped in their own half until the break.
Working forward off a series of penalties, WHS swung onto attack and Holly-Rae Mete burst through tacklers to score.
Dropped ball coming out of their half cost Cullinane, and after WHS were held up over the tryline, they went again from the scrum for Riana Tamati, soon to attend the Barbarians Hurricanes U18 camp, to drive her way over beside the posts.
Keisha Campbell slotted both conversions, and would add a try herself after a blindside sneak from a tryline ruck at the far corner – with WHS continuously blowing Cullinane off their own breakdown ball and getting the shine of the whistle.
Cullinane had a late chance at points but lost possession with the line in sight.
But come the second-half and the underdogs were transformed - strengthening up at the ruck and taking tap penalties where they ran at the defensive line in groups of three.
Again, lost ball cost them a try in the Marist clubrooms corner, but this time WHS spilled a pass as they spread in front of their posts and Elijah Hika snatched it up from the grounded players and forced the ball onto the line.
Waimarie Rauhina, the daughter of former Ratana and Wanganui prop Vaan Rauhina, over 50 Heartland Championship games, was carrying her team forward on her broad shoulders, and shrugged out of tackles to power over the tryline for 19-12.
Cullinane began to find space with basketball-style offloads while WHS gave up three offside penalties in a row, leading to Mete receiving a two-minute yellow card, and no-one was going to stop Rauhina as she took the tap to bulldoze across, with Samantha Rees adding a second drop-kick conversion to tie the scores.
WHS still had some pace options and were trying to attack out of their 40m with the clock ticking down, but with a three-player overlap, the decisive pass was intercepted for Cullinane to have one last chance.
Both sides had a shot at securing the ball, before Cullinane fired a long pass to their two players going wide and Manaia Mason, daughter of another Ratana and Wanganui Heartland legend in Leon Mason, dived in at the corner flag with time up, as the ecstatic bench and support staff ran onto the field before the final kick was attempted.
Cullinane 24 (W Rauhina 2, E Hika, M Mason tries; S Rees 2 con) bt Whanganui High School 19 (H Mete, R Tamati, K Campbell tries; Campbell 2 con). HT: 19-0 WHS.
