After taking a one-point lead into the sheds, Canterbury came out and showed why they are the best team in the competition.
Second half tries to Barrett, Luke Whitelock and Mo'unga would give Canterbury a 12-point lead with just ten minutes to play.
However, Taranaki were far from finished. Fullback Stephen Perofeta crossed the line to give his side hope, but his boot betrayed him as he couldn't convert his own try. Another Barrett penalty kept Canterbury just out of reach as the game wound down.
Still refusing to lie down, Toa Halafihi scored for Taranaki in the 77th minute, closing the gap to five points and setting up a grandstand finish.
Taranaki would get one last crack to steal the game, controlling the ball deep into the 82nd minute but they couldn't produce another try to complete the fairytale finish.
Canterbury 39 (Luke Whitelock 2, Jack Stratton, Jordie Barrett, Richie Mo'unga tries; Barrett 2 pens, 4 cons)
Taranaki 34 (Rhys Marshall, Iopu Iopu-Aso, Stephen Perofeta, Toa Halafihi tries, Marty McKenzie 4 pens, con).
Halftime: 18-17