To their horror, the unthinkable occurred, as heavy underdogs Wanganui Car Centre Kaierau held Byford's Readimix Taihape inches from their tryline for a 20-17 boil-over.
As the full-time whistle blew on the screen, there was no loud reaction, no swearing – the Marist players just quietly walked back to their clubrooms with lowered heads, having missed out by a solitary competition point, despite having a better season differential to Kaierau.
That all-important fourth spot mathematically changed hands multiple times throughout the second half as both Marist and Kaierau came back at their already semifinal-locked opposition.
At Spriggens, without gifted first-five Rangi Kui, Marist gambled on bringing back cast-iron veteran Steelie Koro to run the cutter, with his kicks and cut-out passes as sharp as ever.
But it was upfront where the home side backed themselves, looking to out-work Ngamatapouri's vulnerable set piece, even when they lost half of that advantage as the game went to golden oldies scrums with 29 minutes left.
Instead, Marist just put all their energy into their other advantage – winning in the air from the lineout and then using their bulk to drive off it.
With skipper and flanker Brad Graham proving a safe set of hands, as were locks Lake Ah Chong and try-scorer Brad O'Leary, Marist worked monster prop Keightley Watson up to drive them forward, and then nuggety hooker Jack Yarrall found the gaps to run-in back-to-back tries.
Also covering Kui as goal-kicker, second-five Daniel Kauika was nerveless, slotting four from six, with both misses striking the posts from either touchline.
At 31-24 after Marist repelled a classic deep attacking raid from Ngamatapouri, who could have ended their semi-final hopes right there with an equalising seven-pointer, it was Kauika who stepped up to nail a long-range penalty to make the home side safe with less than a minute remaining.
Before that, the visitors had their moments of ascendancy, leading at halftime 19-14 through some scintillating backline dashes and offloads from the likes of try-scoring and goal-kicking fullback Peceli Malanicagi as well as a freaky double kick-chase try from second-five Jim Seruwalu.
Playing without Kameli Kuruyabaki in the midfield, while co-coach and backline general Brook Tremayne subbed out early as a precautionary measure for his sore leg, centre turned first-five Josaia Bogileka took charge on his former home ground and was sensational with boot and ball in hand.
No8 Ili Navatu made some bone-rattling hits, flanker Samu Kubunavanua was back to a full gallop, while reserve Emitai Logadraudrau sparked a dynamic breakout from their own 22m and then finished off the stunning team try to equalise 24-24.
But the home side responded with character and courage, which made the news only minutes after they finished so heartbreaking, particularly given word had come through earlier that Taihape had a comfortable 17-7 lead.
Assistant coach Darryl Malcolm plainly felt his boys deserved better.
"At the end of the day, we believe we've got the team, there's just a bit of fine-tuning to be done.
"With the team that we've got, we've improved over the past couple of years, and it showed out there today – they had the heart."
Ngamatapouri brought only one specialist reserve front-rower for the game, the Marist bench and coaching staff clearly annoyed to lose their scrum advantage, but the pack did not lose their focus.
"We knew that was going to come, the way it was set up, we just didn't know when it was going to come," said Malcolm.
"It did come, and the word was sent out to just give it everything, tackle your hearts out, and don't give them any ball.
"That's what they did – they played the line for territory for the second half, which was excellent."
Tremayne was confident he'll be fine for Ngamatapouri's trip to Waverley for the club's first Premier semi-final.
"I think the boys played well, and I think if we took our chances we probably could have taken the win today.
"I look back and it was 24-all and it felt like we should have been up. But it just shows that Marist obviously needed to dig deep and get the win. They played quite clinically in the last 20.
"It's tough for us because we wanted to keep the momentum heading into the semis. We don't fault anyone, we had about five or six out today, and all the other boys stepped up, so hopefully we're full strength for the semi."
Marist 34 (J Yarrall 2, I Aki, B O'Leary, K Watson tries; D Kauika pen, 3 con) bt Ngamatapouri 24 (P Malanicagi, J Bogileka, T Seruwalu, E Logadraudrau; Malanicagi 2 con). HT: 19-14 Ngamatapouri.