The gap was widened back to 21 points when Ngane Punivani ran over the top of Jason Robertson to score in the corner.
But tries through Lucas Cashmore, Kumeroa and Reon Paul – the latter off a beautifully worked lineout move – brought the visitors level with plenty of time to steal the result.
That was until a break down the right wing from Chay Fihaki sparked what was ultimately the match-winning sequence, capped off by a try through Toby Bell. With the missed conversion, Canterbury held a five-point lead, but Bay of Plenty had time to work with.
Canterbury had another try late in the contest disallowed after it was ruled to be knocked on in-goal, and Bay of Plenty soon had the ball back with one last shot. The visitors built phases, but ultimately knocked the ball on and Canterbury kicked to touch to lock the Shield away for another week.
Speaking to Sky Sport after the match, a teary-eyed Ah Kuoi, who plays for the Chiefs in Super Rugby, explained why it meant so much to him.
“I’ve lost seven finals and I would love to win one, especially for the Bay. I’ve got a lot of love for this team – my mum’s going to kill me for crying … I love rugby, man. Keep rugby alive,” he said.
“There’s about 20,000 people here, the NPC is still alive. As for how much it means to us in New Zealand, keep supporting us. That game was a wonderful game, a wonderful atmosphere for us to play in. Footy’s still alive, footy’s back and oh my God, that hurt.”
The Shield will be on the line again next week, with Northland heading to Christchurch for a Thursday night challenge and their tails will be up after trouncing Taranaki 42-0 on Friday.
Canterbury 33 (Dallas McLeod 2, Jone Rova, Ngane Punivai, Toby Bell tries; Andrew Knewstubb 4 cons)
Bay of Plenty 28 (Benet Kumeroa 2, Lucas Cashmore, Reon Paul tries; Cashmore con, Jason Robertson 3 cons)
HT: 21-7.