The Steamers rattled on 24 unanswered points to dispatch Canterbury 32-20 in Tauranga on Saturday to make their first final since the playoffs were introduced in 1992.
They will head to the capital to play Wellington, who beat Waikato 29-24 in the other semifinal later that evening.
Bay of Plenty won the inaugural NPC in 1976 but have not etched their name on the trophy since.
They will be hoping to end that 48-year drought by playing some rugby like they did in the second half of the semifinal.
The Steamers trailed Canterbury 13-8 at the break.
Flanker Joe Johnson dived over from a rolling maul and the home team had a handy 8-3 lead.
But the visitors responded through hooker Brodie McAlister and a late penalty from fullback Isaac Hutchinson saw Canterbury go into the break with a five-point buffer.
Veteran midfielder Willis Halaholo smashed through the tackle of Hutchinson to score in the corner early in the second for the Bay.
Winger Leroy Carter made a great finish in the same corner after Lucas Cashmore had slipped through a hole.
Kaleb Trasked added a penalty and, with 20 minutes remaining, the Bay lead 25-13 and were in control of the match.
The Steamers sealed the victory with a sensational try to Semisi Paea, which had started on the Bay’s 22m.
Canterbury chipped ahead.
Cashmore gathered the ball and set off on a short ran before flinging it to Fehi Fineanganofo who busted through on a 50m run.
He got dragged down but managed to offload the ball to Paea to ran the final 20m to score.
Canterbury grabbed a late consolation.
In Wellington, the Lions did a lot of attacking early and finally got some reward when Riley Higgins punched his way past a few defenders and got the ball to halfback Kyle Preston to score under the posts.
Makeshift Waikato winger Ollie Mathis, who normally plays on the openside flank, produced another piece of individual magic.
Aaron Cruden shovelled him a desperate pass when he fell under pressure deep in his own half.
Mathis chipped ahead with his right foot, got a nice bounce and toed it through with his left then used his gas to beat the cover and score a 70m try.
He is some player that young man.
Waikato took the lead through a penalty try and Wellington lost Higgins to a yellow card.
He batted down a pass when the Mooloos had three-man overlap.
Wellington prop Siale Lauaki crashed over from close range to cut the gap to 17-15 at halftime.
Callum Harkin set up the next five-pointer for Wellington.
He chipped ahead and regathered an awkward bounce.
Fullback Tjay Clarke got in support, drew the defence and got if off to Preston to run in for his second try.
The Lions rumbled over from a lineout drive to extend their lead to 29-17 with 12 minutes remaining.
Waikato chipped away and Mason Tupaea went over for a nice team try to give themselves a late chance, but it was not to be.
