"That was a huge win for us. The boys had to stick in for some tough periods there," Northland captain Matt Moulds told Sky.
"Auckland really wanted to stamp their mark; they didn't want to take the points, they wanted to take seven off us and our boys had to dig deep."
The result could have been different for Auckland had it not been for their execution.
Auckland had at least two tries go begging in the second half; a strong scrum from five metres out steamrolled over the Northland line only for an Auckland player to knock the ball on in attempting to score, and wing Salesi Rayasi was unable to plant the ball before losing it backwards on another occasion. Rayasi's attempt to sell the try might ultimately have cost Auckland too, as the loose ball fell at the feet of a teammate but the referee had called time to check Rayasi's grounding.
Northland started well, with left wing Heremaia Murray finding plenty of space and putting his pace to good use, and the hosts found good territory. They opened the scoring through hooker Moulds from close range before adding a Rivez Reihana penalty to go ahead by eight.
After struggling to get into the game for the opening 20 minutes, Auckland began to hit their stride midway through the first half and quickly took over proceedings.
By the time Auckland wing Tomas Aoake scored in the corner 37 minutes into the contest, Northland had almost doubled Auckland's tackle count and a try late in the half to hooker Robbie Abel saw Auckland go into the break with a slim lead.
That lead was quickly taken away when Murray flaunted his pace out wide to finish off a move in the corner, but again Auckland began to take over the match.
The majority of the second half was spent deep in Northland territory as the side conceded plenty of penalties and kept having to defend against scrums. While they did not lose a man to the bin because of this, eventually the referee awarded a penalty try to Auckland after continued infringements.
With a 19-13 lead, Auckland looked set to take over on the scoreboard. However they couldn't make the most of their possession and territory. Instead, it was Northland who took the lead back with an end-to-end attack.
Murray found some space in the Auckland line in broken play and Northland went on the front foot from there. With a scrambling Auckland line, reserve hooker Bruce Kauika-Petersen eventually went over.
The conversion gave Northland the lead, but Auckland again took it back less than five minutes later through a Harry Plummer penalty goal.
But there was one last twist left in the match, with Reihana slotting a penalty from 45 metres out with 90 seconds left on the clock to lead the Taniwha to a famous win.
Elsewhere, Waikato beat Taranaki 21-6 in rugby's return to Yarrow Stadium, while Hawke's Bay beat Northland 28-19 in the first of the Farah Palmer Cup championship semifinals.
Northland 23 (Matt Moulds, Heremaia Murray, Bruce Kauika-Petersen tries; Rivez Reihana con, 2 pens)
Auckland 22 (Penalty try, Tomas Aoake, Robbie Abel tries; Harry Plummer con, pen)
HT: 8-12
