Tasman made it two wins on the trot in the ITM Cup after seeing off Northland 34-29 at Trafalgar Park in Nelson on Thursday.
The five tries to four defeat consigned the Taniwha to a bottom-half finish in the competition with one round still left to play.
Behind 8-19 at the interval, Tasman put on 19 unanswered points in as many minutes after the resumption with the sort of form which belied their lowly 12th placing in the standings.
Tasman's comeback was sparked by a controversial try to wing Blair Cook, who was awarded a try by the TMO early in the second spell despite replays indicating he had lost control of the ball over the line.
Minutes later Tasman snuck in front on the back of a fine individual try to wing Kade Poki, who sliced through a hole then stepped the last defender en route to the line.
Having built some momentum, they built on that when the forwards constructed a try to prop Fai Mika after a dominant scrum led to a concerted drive which Northland were powerless to stop.
Full-back Lachie Munro cut the deficit for Northland with a penalty in the 65th minute but Tasman again displayed their confidence when a break from Tom Marshall was completed by number eight Poutasi Luafutu who was not to be denied from 20m out.
But Northland refused to buckle, striking back a few minutes from full-time when replacement forward Tim Dow was driven over the line for their bonus-point try, with Munro's conversion dragging his side to 29-34.
Northland gave themselves a chance to snatch a late win when a penalty left them with a line-out inside the Tasman 22 in the final minute but the visitors lost the throw - and with it the game.
Tries: Jack, Cook, Poki, Mika, Luafutu
Cons: T Marshall 3
Pen: T Marshall
Tries: L Munro, Griffin, Wallis, Dow
Cons: L Munro 3
Pen: L Munro
Tasman: 15 Tom Marshall, 14 Kade Poki, 13 Afeleki Pelenise, 12 Jack Umaga, 11 Blair Cook, 10 Robbie Malneek, 9 Steve Alfeld, 8 Poutasi Luafutu, 7 Shane Christie, 6 Glen Gregory, 5 Chris Jack (c), 4 Anthony Elisala, 3 Ben Franks, 2 Vernon Fredericks, 1 Fai Mika.
Replacements: 16 Francis Smith, 17 Craig Moore, 18 Ben Coman, 19 Jonathon Poff, 20 Kaide Whiting, 21 James Marshall, 22 Sione Holani.
Northland: 15 Lachie Munro, 14 Simon Munro, 13 Jared Payne (c), 12 Aaron Bancroft, 11 Iwi Hauraki, 10 David Holwell, 9 Rhyan Caine, 8 Cameron Eyre, 7 Joel McKenty, 6 Dean Budd, 5 Mark Burman, 4 Roy Griffin, 3 Bronson Murray, 2 Mikaele Tuu'u, 1 Matt Wallis.
Replacements: 16 Tim Dow, 17 Ross Wright, 18 Pat O'Connor, 19 Dan Pryor, 20 Luke Hamilton, 21 Adam Clarke, 22 Mateo Malupo.
Referee: Vinny Munro