But from the 65th minute - entering what Whanganui coach Jason Hamlin had called “the championship minutes” - with the hosts having regained the lead at 21-19 after sustained ball retention on the Thames Valley line, everything seemed to blow wide open.
A further four tries were scored, along with what proved a crucial long-range penalty from Thames Valley’s standout goal-kicking winger Fletcher Morgan (five from six), who finished with a 21-point haul - including a double.
Thames Valley’s other estimable winger Harry Lafituanai scored a brilliant individual try from a chip and regather in the corner, leaving his team uncatchable at 36-28 with less than two minutes remaining.
Whanganui skipper Dane Whale had to make a big call with a penalty less than 20 metres out and time up on the clock, having taken over the kicking from debutant fullback Sheldon Pakinga when he came off with a sore leg.
Needing any kind of score to get a second bonus point, with not enough time left for another, Whanganui went for the lineout and thankfully came up trumps with a drive that some backs joined to put fellow debutant reserve Alesana Tofa over the line.
It was a shame that reserve lock Matt Ashworth, who came on early in the first half for the injured Peter-Travis Hay-Horton, did not get a victory on the occasion of his 15th blazer match.
Whanganui had no real issues in the lineout, Josh Lane, Ashworth, industrious flanker Doug Horrocks securing most of their ball, while the scrum did not dominate the big opposing Thames Valley pack but at least held them to a stalemate.
The biggest detriment was making the advantage line, as carriers already slowed in the mud were being sized up by Thames Valley’s musclemen - it sometimes took three or four hard carries into contact just to make five or 10 metres’ progress.
The visitors’ zippy halfback Leroy Neels found gaps, scoring one close-range try and setting up Morgan for his second.
Whanganui’s brains trust of Whale and halfback Lindsay Horrocks had a hand in everything - Horrocks setting up three of his team’s tries with a perfect box kick and then two ruck darts with flick passes near the line.
But just like in pre-season, the home side couldn’t put their opposition away in the final minutes.
“They beat us in the middle of the field, we weren’t able to gain any momentum because our on-the-field carries weren’t going anywhere,” said Whale.
“We need to work to identify that early and possibly change. We changed at halftime.
“We needed to adapt our plays, but we didn’t do it well enough.
“It was a great game of rugby - 59 points - we were just on the wrong side of it.
“[The last 15 minutes] there were a few more linebreaks and people running holes, teams get tired and you can pick them off a little bit better.
“We’ll have a lot to work on for next week. Just that speed and intensity, even with the harder pre-season games, there’s that little bit more fire when the competition starts.
“It would have been nice to take that one, but I think we’ve got plenty to learn and take into Buller next week away - probably a nice one to follow up a hard loss.”
Seeing that the usual linebreakers were not getting through against Thames Valley’s pack and midfield, Hamlin had given halftime instructions to try other avenues, “but we just didn’t quite get it”.
“But again, when we held the ball and we were able to play down here [the attacking 22m zone] and play a good position, we just wear teams out.
“We wore them out, but we just gave up points too easy. That chip-and-chase, and guys not being connected enough on ‘D’ - 36 points, you shouldn’t expect to win.
“There was enough good things, but this will come back and haunt us, I dare say.”
Not getting the normal roll-on through the phases brought the game back to 50-50 moments, where loose ball could fall for Whanganui but might be fumbled in the mud.
“We did do it [right] a couple of times in the first half - we had people running on to balls, hitting weak shoulders and getting right over the ball.
“But then we were static and stationary, waiting to catch the ball when there was no momentum in possession - trying to catch it and then do something.
“A bit of trickery in our ball handling with Samu’s [Kubunavanua] try under the posts and Doug’s try under the posts - we got the tools there, but just played a really good side who were up for it and came out and bashed us.”
Thames Valley 36 (F Morgan 2, L Neels, S McCahon, H Lafituanai tries; Morgan pen, 4 con) bt Whanganui 33 (A Vakarorogo, T Seruwalu, S Kubunavanau, D Horrocks, A Tofa tries; S Pakinga 2 con, D Whale 2 con). HT: 14-12.
