A hard-fought draw against Kamo in Kaihu stopped the Western Sharks from also taking home their fourth win as the sides battled to a 15-all draw when the final whistle blew.
Working through a tough game against a competitive Hikurangi will put Waipū in good stead going into the remaining games.
"Hikurangi played really well, they should be proud of how they performed, we were just lucky the ball bounced our way on the day," Waipū coach Graham Dewes said.
After coming out of the changing rooms cold and conceding the advantage, Dewes said he implored his side to tidy up their simple errors.
"We didn't start well, we got penalised off the park and [Hikurangi] took advantage of that.
"So at halftime, when they were leading, I just said to cut down the error rate, cut down the penalties and just hold onto the ball."
Dewes highlighted stand-in captain and hooker Ben Tou as one of players who performed well and said Tou stepped up with the team's usual leaders out with injury.
"I think Ben just led from the front and we were able to be stronger at the lineout and the scrum area which was the difference on the day," Dewes said.
Although happy with the latest of four wins, Dewes said the team needed to focus on the competition one game at a time with several other sides close behind in the title race.
"It's a good start in terms of the season but it's still early stages," he said.
"Just from the first few games, there are probably six teams who stand out and the competition could go to any of them, so we just have to take each week as it comes, stay humble and keep working."
Hikurangi coach Alistair Rickey said the images of Waipū crossing to line to score the winning try with 10 minutes to go was fresh in his mind, but felt the game was an evenly-matched one.
"We played really well and in good sport, it was a good arm-wrestle of a game, both teams trading points," he said.
"They're unbeaten and we've had a bit of an up and down season but we've shown we can compete against big teams."
Hikurangi sit fourth from the bottom of the table and Rickey hoped his team could clean up the simple mistakes that let them down this weekend before they take on their rivals, Mid Northern, next weekend.
"The boys' spirits are up now, it's not the result we wanted but we did everything pretty well, just a couple of crucial mistakes which hurt us."
In the round's other games, Old Boys Marist beat Mid Northern, 48-15, Wellsford beat Kerikeri, 35-20, and Hora Hora beat Otamatea, 50-25.