They pounded Marist's line mid-way through the half, receiving a multitude of infringement penalties from Viliamu, who eventually sinbinned Marist reserve Marek Willis.
Yet the thin green and white line held - Koro defying physics with an amazing try-saver to swamp reserve back Hoani Pahl-Long when he was in mid-air over the chalk and drag him back into the field of play.
The entire Marist pack can hold their heads up, as to make up for the overlap they would move one forward into the midfield on each specific set play and trust the remaining seven could still contest with the Kaierau eight.
"I thought our scrum was actually holding its own, so we didn't sacrifice when we didn't need too," said delighted coach Jason Hamlin.
"Two seasons ago, we would have lost that game "
Kaierau coach Denis Edwards knew his side had not executed when it mattered.
"We were outplayed, they wanted it more than we did.
"The penalty count was atrocious in the first half, in the ruck and maul area, for whatever reason. [Forward passes] three or four times there - it would have made the difference. It's a hard road for us now. But take nothing away from Marist, they played well."
Running good inside passes and working forward of surging runs by prop Jack Yarrall and No8 Fiatau Faalili, Kaierau got a penalty in front for Hyland to get them away to a good start.
But Koro was soon threatening out wide with Koniferedi and Bogileka looming, while on the opposite side Simon Dibben was a headache for Kaierau on the kick returns, with the home side costing themselves by getting up too quickly with offsides on defence and forward passes on offence.
Marist first-five Sam Monaghan, who continues to mature, landed two penalties and then after a Kaierau spill, the Marist forwards worked forward with pop passes and No8 Nathan Puketapu dashed under the posts.
Kaierau lost Wilson for ten minutes and Koro made them pay with the perfect pass to a charging pocket battleship in hooker Richard Campbell for 20-3 approaching halftime.
But it seemed the dynamic would change with Kaierau's penalty try - as a risky Lama cross kick in his 22m saw winger Anaru Saurara dash away from a slipping Dibben and sprint 60m before feeding centre Kameli Kuruyabaki, with Kaierau's support flicking it around until a diving Bogileka collared Hyland high around the neck and leaving him prone on the field - Viliamu jogging to the posts and then pulling the red.
Far from discouraged, Marist went on the attack right after the break as a strong Dibben run to the far corner stretched Kaierau, then the long passes came back the other way for reserve Tavita Tui to dummy into the gap and score.
Kaierau replied quickly with a Pahl-Long penalty for 27-13, and for the next 20 minutes threw everything at Marist with penalty scrums, lineouts and quick taps, only too be thwarted at every turn even with only 13 opposing them.
Koro's amazing tryline tackle and Kaierau losing possession shortly afterwards took the fight from them, as Marist cleared their territory and worked Monaghan into position for two 40m penalty attempts, nailing the second.
Marist still had just enough time for a bonus point try as Kaierau were penalised and another long Koro pass found Koniferedi who scorched over for a deserved five-pointer.
Marist 35 (Nathan Puketapu, Richard Campbell, Tavita Tui, Simeli Koniferedi tries; Sam Monaghan 3 pen, 3 con) bt Kaierau 13 (Penalty try; Dion Hyland pen, Hoani Pahl-Long pen, A Saurara con). HT: 20-10.