Some slick offloads among the forwards freed up the maestro, Craig Clare, to charge for the corner, jumping through a tackle, and putting second five Anaru Haerewa over in the corner for 10-0 in the first quarter.
But you relax against Ngamatapouri at your peril as, from a scrum just inside halfway, the visitors fired the ball wide to standout winger Peceli Malanicagi, who cut through the line, sprinted away, then left the two cover tacklers in front of him absolutely laying to close the gap after 25 minutes.
Ngamatapouri amended the script further five minutes later when halfback Tasi Kabukaua made a dinky chip kick from the back of an attacking ruck and Malanicagi flew through to catch it on the full and race in for a double, with first five Brook Tremayne booting the underdogs into the lead.
His team kept the pressure on and earned a penalty in front for Tremayne to extend their advantage to 15-10 at halftime.
With their chance at the Premier three-peat very much in danger, Border needed composure and there's none better for that than Clare who, now he had the wind behind him, slotted a 38m penalty five minutes after the resumption, to close the gap.
The forwards then delivered again as prop Hamish Mellow took a pass off his bootlaces and fed lock Toby Lennox, who powered through a gap and found No 8 Semi Vodosese, who pulled in three cover tacklers before offloading back to Lennox for a 20-15 turnaround.
But if the hosts felt the visitors would fade away they were mistaken, as Ngamatapouri produced sustained attack from the pick and go, securing a couple of penalties, and despite Jim Seruwalu's long pass being nearly intercepted, fullback Josaia Bogileka recovered it and went careening towards the corner flag, with winger Emitai Logadraudrau right there to equalise in the 66th minute.
Border still backed their set-piece, in particular their scrum, to keep Ngamatapouri contained, and eventually, they earned a ruck penalty for Clare to once again boot them into the lead entering the last 10 minutes.
When co-captain Angus Middleton trapped Ngamatapouri in the ruck for another Clare penalty from 25m out after 76 minutes, Border had to figure they were all-but home.
All-but, when you play Ngamatapouri, who despite an under-pressure scrum and ferocious cover tackling, clawed their way back up field, getting a couple of tap penalties.
Centre Kameli Kuruyabaki finally broke the wall, and only a desperate dive from Tom Symes prevented Logadraudrau from scoring. Then Ngamatapouri worked the ball back towards the middle where, in a stunning finish, Bogileka drove over the line, only for the referee and linesman to confer and rule he had been held up on the game's last play.
Players on both sides collapsed, too spent to move, but when all is said and done, Border have booked another date at Cooks Gardens with their rivals Byford's Readimix Taihape.
It will be the power clubs' third championship game against each other in four years, and their fourth in the last seven.
Border 26 (R Tikoisolomone, A Haerewa, T Lennox tries; C Clare 3 pen, con) bt Settlers Honey Ngamatapouri 20 (P Malanicagi 2, E Logadraudrau tries; B Tremayne pen, con). HT: 15-10 Ngamatapouri.
