In one of the closest finishes in years, Dunedin Technical finished just one point behind Caversham after it demolished Grants Braes 6-0 at Ocean Grove.
In just his second season in charge, Caversham coach Richard Murray was elated to regain the title.
"It's awesome for the lads.
They've gone through a whole league season unbeaten, and all the hard work has paid off."
Caversham will play Mainland Football champion Ferrymead Bays, in Christchurch this Saturday, to decide the South Island championship.
Northern competed well in the opening part of the match on Saturday but lacked real strike power to trouble Caversham keeper Liam Little.
The scoring started in the 22nd minute, after Northern cleared a corner and players pushed out to clear their lines.
Impressive central defender Jude Fitzpatrick stayed just onside as a deft chip was delivered back into the attacking zone, which Fitzpatrick finished with composure.
Fitzpatrick had his second just before the break, when he nodded in a far-post header to give Caversham a fair reward for its first-half efforts.
The second half produced more good chances for Caversham, as Northern showed signs of a two-week layoff. Some sloppy defensive work in its own penalty area gifted Evan Jones a simple tap-in opportunity.
The dangerous Harley Rodeka robbed Northern keeper Blair Brown of possession n the 68th minute and dribbled the ball into the goal to claim his first.
Caversham midfielder Seamus Ryder capped off a fine match, displaying some sublime touches and first-time layoffs to complete the scoring in the 85th minute, when he finished an attack down the right.
In the other catch-up match, Dunedin Technical proved too strong for Grants Braes, continuing its recent excellent form and putting six past a depleted home team.
Tim McLennan opened the scoring for Technical in just the fourth minute, when he attacked the penalty area and finished with a strong shot.
Aaron Burgess got his first with a clever chip over the keeper from 20m out.
Arguably the goal of the game came when Burgess expertly chested a throw-in to Alistair Rickerby, who smashed home a first-time volley, giving the keeper no chance.
A Justin Flaws penalty and second-half strikes to Rickerby and Flaws completed another dominant performance for this season's runner-up.
By Wilson James.
