"Pretty much some of the standouts were our Whanganui boys."
Utility forward Hamish Bennett started the game at flanker and scored a brilliant try to open Heartland's account - snatching an overthrown Southland lineout ball and racing 60m to the line.
"Just dashed out of a lineout, beat the halfback, then went around the fullback to score," said Ratima.
Bennett would get his hands on several Southland throws in the game.
From 5-5 at halftime, Heartland went on with it in their final 35 minutes as a team, with Hakaraia scoring the last try from a ruck on the line when he forced his way under a mountain of defenders.
Ratima said they had analysed the Southland set piece and although they had bigger lads, they were slower getting around Owen Delany Park.
In addition to fellow locals Ethan Robinson and Jessy Kemp having good games in the backline, Whanganui High School player Blair Osborne had just joined the squad to cover injuries and was creative in the midfield - including helping set up an 80m team try.
Ratima said the squad deserved a victory, after they lost narrowly to Tasman 20-17 despite scoring three tries to two, then being "a bit flat" against Northland in the 18-8 loss.
"There were two tries disallowed, and that's all I'll say about that," he said.
The side's victory was well received by the spectators in Taupo.
"They're sort of like the pet project for the NZRFU - they're the ultimate underdogs, only having a week to prepare, or two days really," said Ratima.
"But once they put on that black jersey, they go up another level or two."
The Michael Jones Trophy for their division was won by Counties Manukau, who beat Bay of Plenty 35-20 in the final, while the top tier Graham Mourie Cup was won by Waikato, who defeated Auckland A 25-22 in their final.