Turanga winger Amoe Wharehinga put her side in front 12-10 with a try, only for Hamoterangi to retake the lead when No.8 Sensameila Hina charged from the back of a scrum inside the 22 to score.
It was shortlived as Shelford grabbed the ball from the base of a ruck on the Hametorangi 22m line and burst through to score between the posts.
Hiko kicked the conversion for 19-15 and a lead they would not reliquish.
Wharehinga put them further in front when she received the ball wide on her own 10m line and weaved and stepped her way through Hamoterangi defenders to score under the sticks.
Hiko’s conversion extend the Tūranga lead to 26-15.
Hamoterangi upped their intensity and were rewarded when centre Waiotemarama Parata-Haua dotted down between the posts and first five Maraea Green nailed the drop-kick conversion for 26-22.
Halfback Maia Rickard all but sealed the win when she fed the ball into a scrum on halfway, regathered it and ran down the blindside untouched for 31-22.
Hamoterangi had the final say with a try to openside flanker Hinewaipounamu Rangihuna.
Tūranga head coach Lenny Ferris said they had been working hard on producing cleaner ball from the breakdowns and getting the ball to their wingers.
“We initially tried going through the middle,” Ferris said. “But it was our ability to get the ball out wider to the edges where our strong backs are where we made a lot of yards.”
Ferris said the coaches gave the team structure and key instructions which was combined with their natural instinct to keep the ball alive and run it.
The win came after losses to King Country (32-15) in Week 2 and Whanganui (32-10) in Week 3.
“It was more of a relief than anything,” said Ferris, whose team started the competition with a 31-16 defeat of Thames Valley.
“The girls were working towards the win and there was a bit of hype around it, too.”
The win moved Turanga to 10 points and fourth on the six-team table headed by Whanganui.
Turanga host fifth-placed Wairarapa Bush in Wairoa in Week 5 games while the sixth-placed Coast are away to Whanganui.
Week 5 games are followed by a finals weekend in Taupō.