Max Thomas popped up on the right after a neat combination to fire over a low cross for the Central Brown striker to steer home.
The boys in blue may have been three or four up were it not for some inspired goalkeeping from Edward Trubshoe in the Te Atatu goal.
He denied two point blank opportunities within the space of five minutes and then produced a fine one handed save from a left footed Thomas shot that curled toward his top right hand corner to ensure that the score stayed at 1-nil.
Before the half was out, Andrew Dalton equalised for Te Atatu - giving them hope and leaving everything to play for over the season's final 45 minutes.
The second half started cagily, nothing really of note to report until midway through the half when Northland substitute Jordan Rudman finished another move from the right-hand side into the top corner from eight metres in the 71st minute.
The rest of the game saw Te Atatu try to find a way back but when they did, it was too late.
Dalton curled home his second into the top right-hand corner via a free kick from 30m, although at 90 minutes, it was ultimately too little too late.
Northland head coach Dan Johnston said: "I'm glad to see the back of this season, it has been a real battle but we survived and now we can move on. The lads pulled through when we needed them to but we shouldn't have allowed ourselves to get into this situation. Next year will be better and a lot of the young players in our squad will be stronger from this experience.''
