Industrious hooker James Parsons, fleet-footed winger David Raikuna (2), and classy skipper Chris Smylie crossed the tryline for Harbour.
Wellington scored a five-pointer in each half with big flanker Faifili Levave and All Black discard Hosea Gear finding the tryline.
Sopoaga was the difference between the two sides, kicking seven from seven with four penalties in the secondhalf for a personal tally of 19 points.
Harbour finished the firsthalf with the wind in the sails after scoring three tries to the Lions one with Smylie, Parsons and Raikuna crossing the tryline.
Levave's try was converted by Sopoaga who added a penalty but Harbour's enthusiasim to finish on a high note in front of their faithful provided plenty of early inspiration.
Trailing by 13 points at the break, Sopoaga kicked three penalties to take his side within four points of the lead after 55 minutes.
With the Lions creeping on Harbour's lead, Gear burst onto Charlie Ngatai's pass to score and give his team the lead for the first time in the game.
Raikuna, who has been Harbour's most potent back this season scored his second try, making a midfield break which was carried on by Wulf before the Fijian took the final pass to score and reclaim the lead 28-26 with 15 minutes to go.
Sopoaga's fifth penalty of the match with less than ten minutes remaining was enough to take the spoils by a solitary point.
Wellington 29 (Faifili Levave, Hosea Gear tries; Lima Sopoaga 5 pen, 2 con) North Harbour 28 (David Raikuna 2, Chris Smylie, James Parsons tries; Ben Botica 2 pen, con). Halftime: 23-10 (NH).
- HERALD ONLINE
