Auckland City opened the scoring when Manel Exposito evaded a Brian Shelley challenge to score after 15 minutes to put the navy blues in front.
But Waitakere United were level on the half hour mark when Roy Krishna slammed home a Chad Coombes cross on the half volley.
The West Aucklanders were in front two minutes later when Allan Pearce glanced home a Coombes corner to see the lead change hands, the fifth time Pearce has scored in an ASB Premiership grand final.
In an end to end affair, both sides created a plethora of chances with goalkeepers Tamati Williams and Danny Robinson distinguishing themselves with a series of vital saves.
With 16 minutes left, Exposito levelled the game with a carbon copy goal of his first effort, bending a shot beyond Robinson that skidded off the wet surface to make it 2-2.
The game took another dramatic twist three minutes later when substitute Simon Arms was sent off for pulling Krishna's shirt with the Fiji international through on goal.
Down to ten men and looking out on their feet, Auckland City produced a moment of sheer delight for their away support when former Waitakere United player Chris Bale slammed home from close range with just a minute left on the clock.
With Auckland City 3-2 up and only seconds left, Waitakere United substitute Tristan Prattley wound in a wonderful cross that saw Krishna cushion a delicate header past Williams to take the game to extra time.
The match was settled ten minutes into the first period of extra time when Pearce scored a replica of his first with a repeat glancing header from a Luiz del Monte corner to give Waitakere a 4-3 lead.
Waitakere had a tremendous chance to seal the game with a fifth goal after Krishna sprung the Auckland City offside trap, rounded Williams, only to hit a weak shot into the side netting.
At the other end of the field, Danny Robinson produced key saves from Gustavo Souto to keep Waitakere United's quadruple championship charge on track.
Auckland poured players forward in desperate search of yet another equaliser and almost got a late reward when substitute Emiliano Tade peeled away from Tim Myers only to sky his close range header high over the crossbar.
Victory gives Waitakere United a domestic treble of ASB Charity Cup, ASB Minor Premiership and ASB Premiership, and sets up the Paul Marshall-coached club for a crack at a clean sweep with the OFC Champions League season kicking off on March 30.
Marshall is also the first coach to win the ASB Premiership with two different clubs and Waitakere overtake Auckland City as the club with the most championship wins of five in nine seasons.
In the ASB Youth League final, Auckland City overcame a solid Otago United to lift the junior title for only the second time in navy blues history.
After a goalless first half, Jordan Roberts opened the scoring from the penalty spot on 67 minutes, before Thomas Konusi doubled the lead ten minutes later. Skipper Dean Lausev sealed the result with a long range shot with just six minutes left to confirm a 3-0 win for the Chris Zoricich-coached team.
For highlights of the ASB Premiership final between Waitakere United and Auckland City click here
Story courtesy of New Zealand Football.
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