They were assisted by the visitors just having an unhappy game, belying their fifth-placing on the table, as they made far too many handling errors to be competitive and gifted Whanganui time and territory to get their systems right.
And it was all systems go, as Whanganui worked their ball runners into position rather than asking them to create the initial impetus – with player-of-the-day winger Alekesio Vakarorogo scoring a record-equalling four tries.
Gifted No 8 Semi Vodosese continued his sixth-sense connection with halfback Lindsay Horrocks to work into position for two tries beside the posts, while Whanganui ran their full bench on early in the second half yet lost little in the way of cohesion – ultimately scoring 38 more points in the last 40 minutes.
It would have been terrifying for the visitors to think where the scoreboard might have finished had the track been bone dry as, given the conditions, Whanganui still smartly used their tactical kicking game – fullback Ethan Robinson coming to the fore until being forced off late with a foot injury.
Caked in mud, try-scoring second five Timoci Seruwalu and flanker Samu Kubunavanua revelled in the open style of play, while the front-row group of Ranato Tikoisolomone, Bradley Fountain and reserve Keightley Watson imposed themselves in the scrum and maul.
With a home Meads Cup semifinal now very much the focus, coach Jason Hamlin had the 15-man performance he has been searching for this past month.
"This week, we probably got another metre of space, and we can see when we get some quick ball, bodies in motion, just how effective we can actually be.
"The difference was the first 10 minutes. There was just a lot more intent, people were hitting rucks, clear on their roles, what they're doing, it was a combined effort.
"Outside of that, was just some good rugby players, playing some good code."
It would have been understandable in the second half, with Buller struggling, if players started to have a go by themselves, but Whanganui stuck to the task of putting players in space or getting in behind to drive them forward.
"That was the message at halftime, just 'job half-done. We've had that where we're beating teams and let the second half get away from us," said Hamlin.
"As much as it was nice to see them put some points on, from a coach's point of view, the most important point for us was the [Buller] score was seven.
"We're striving for that performance - you may not get it every week, but that's the goal to strive for."
Hamlin gave a tip of the hat to Vakarorogo, who accomplished a feat even his vaunted cousin Vereniki Tikoisolomone did not achieve in Whanganui colours - scoring a quartet of tries.
"That was very good, but again, work rate for Aleke – keeps turning up, keeps putting himself in those positions.
"It probably hasn't gone his way a heck of a lot this year so far for that, but today he just showed what a quality footballer he is."
Skipper and try-scorer Dane Whale agreed.
"Happy for our wingers to be scoring tries – that's what they're there for.
"I think last week, we just didn't have that enjoyment factor, and you could see it in the boys' eyes today that they just wanted to play.
"That fun component comes when everything's rolling on."
Against Poverty Bay, Whale noted players had attacked individually while others seemed to hesitate, but on Saturday everyone got to where they needed to be to lay the platform.
"We just weren't looking after the ruck last week, so we really reiterated that on Tuesday that wasn't good enough, so we wanted to set that standard today.
"I thought, right through the paddock that was done. Handling errors killed us last week and that started creeping in a little bit at the end, but still proud of the boys' efforts."
Whanganui 83 (A Vakarorogo 4, S Vodosese 2, J Bogileka, S Kubunavanua, T Seruwalu, J Yarrall, E Malo, J Lane, D Whale tries; E Robinson 8 con, Malo con) bt Buller 7 (J Pitman-Joass try; J Parker con). HT: 45-7.
