Auckland have beaten North Harbour in the 'Battle of the Bridge' at Albany to book their spot in the NPC semi-finals.
Despite dominating set-piece and territory, the visitors were forced to come from behind to snatch an unlikely 21-18 victory to keep their title hopes alive for another week.
Just as it looked as if the game was headed for extra time, second-five Harry Plummer coolly slotted the game-winning penalty after the hooter.
The home side were limited on attack in the opening exchanges of the game, but stretched the Auckland defence, forcing five missed tackles in the first 10 minutes.
Auckland opened the scoring with a penalty goal to second-five Plummer, after a strong scrum just outside the 22m.
For all their dominance at set-piece, the visitors struggled to take advantage, and instead, allowed Bryn Gatland to level things up with a penalty of his own.
Auckland No.8 Jackson Pugh looked to have scored the game's first try, but was penalised for not releasing the ball in his second attempt at the tryline.
Instead, they were forced to settle for another penalty goal, with Plummer capitalising on Nic Mayhew's infringement at the breakdown.
Returning All Blacks loose forward Akira Ioane struggled to impose himself in the first half, and was penalised at the ruck, but for Gatland to hit the post in his penalty attempt.
But Gatland would make amends just moments later, showing great strength to ride three tackles and score the game's first try, after Cameron Sufoa was tackled just short.
And if it couldn't get any worse for Auckland, winger Tomas Aoake was shown a yellow card for making contact with Gatland's head in the movement, while prop Angus Ta'avao was stretchered off with an apparent head injury.
Harbour finished off a fantastic first with another try to the competition's star winger Tevita Li, who crossed right on halftime to give his side the 15-6 lead at the break.
As soon as Auckland could welcome back Aoake to the field in the second half, they lost All Black Roger Tuivasa-Sheck to a yellow card, after he collected Li in the air.
But Auckland's set-piece dominance finally paid off, with Ioane muscling through a couple of defenders after another lineout drive to stretch out and score his team's first try.
Plummer had a chance to put Auckland in the lead in the 67th minute, but his penalty strike at goal fell just short of the crossbar.
Instead, Stevenson nailed a mammoth 58m penalty goal to extend Harbour's lead to 18-13 with 10 minutes to play.
Fresh off his try-double last week, Auckland replacement Terrell Peita crashed over for the game-tying try, after several penalty advantages.
With momentum well and truly in their favour, Auckland marched their way down field, before winning another kickable penalty just outside the 22m.
Plummer put an off night with the boot behind him to snatch an unlikely win for Auckland over a seemingly cruising Harbour outfit.
Harbour 18 (Gatland, Li tries; Gatland 1 con, 2 pen, Stevenson 1 pen)
Auckland 21 (Ioane, Peita tries; Plummer 1 con, 3 pen)
