Wanganui continued to make silly mistakes and were heavily penalised throughout the match for the indiscretions.
Wanganui second-five Pehira Huwyler put the ledger straight with a try 20 minutes into the first spell which was converted by Rawiri. The score stood at 12-6 before Wairarapa-Bush No 8 John McFadzean crossed for a try which was converted by the accurate boot of Walters.
Wanganui first-five Areta Lama was yellow carded just before the break, the victim of repeat offences by his teammates with the score standing at 13-12 in Wairarapa's favour.
In the second spell Wanganui were still a man down with Lama still in the sin bin and a try from Wairarapa centre Paul Tikomainaivalu came from a badly taken kick for touch by Wanganui's replacement first receiver Tauriki Manawatu.
With the score at 20-12 in the visitor's favour Wanganui were looking decidedly shaky until Nick Cranston started a move that ended with Ace Malo sending an inside pass from the touchline to Tremaine Gilbert who scored. At 20-17 Wanganui signalled they were on the way back. Tries by halfback Lindsay Horrocks, Shaun McDonough, Aaron Yadiga and captain Vaan Ruhina late in the second spell all of a sudden made Wairarapa-Bush looked decidedly ordinary.
A relieved Hoskin said he was pleased with the way his new players handled themselves at this level for the first time and he welcomed the opportunity to try new combinations.
"We finished extremely well and I was happy with the combinations we managed to test out. This match has given us a lot to think about before naming a Heartland squad. I was able to field two separate backlines and we still have others to come into the wider squad before making an final decisions. Over all I was pleased with the outcome," Hoskin said.
Wairarapa-Bush coach Mark Rutene said while a loss is a loss, the game allowed him and his team to assess how newcomers stacked up at Heartland level.
"We had a few missing today, but it was a good chance to see which players were up to this level. We will go home and think about how we performed, but then it's always tough coming up to play Wanganui," Rutene said.