The Bay backs looked dangerous going forward but the home side seemed unable to capitalise on their territorial advantage. Northland began edging back into the game, led by inspirational captain Rene Ranger, although they were hampered by poor discipline.
A spark of individual brilliance from left winger Mateo Malupo gave Northland its first real opportunity of the match, but his chip ahead after a great run fell into the hands of Jack Ram who was unable to hold on, allowing the Steamers to clear.
Four minutes later Malupo was at it again, sprinting down the flank before his kick through was fielded by Steamers winger Jack Wilson. Wilson's attempted clearance was charged down by replacement Matt Wright who regained the ball and went over to score. Ash Moeke converted from out wide to make it 10-7 at the break.
The Steamers needed to turn their dominance into points and they came out fired up for the second half. Ten minutes into the second spell a patient build-up by the pack got them to within inches of the Taniwha's line. That man Goodwin was again on hand to dive over for his second try.
Northland went down to 14 men at 61 minutes when David Hall was sinbinned and the Steamers took full advantage. Reporoa boy Axtens ran in for his side's third try off the back of a scrum, giving Noakes an easy conversion.
The bonus-point try followed soon after and earned the biggest cheer of the day from the home crowd. Replacement Mafi Kefu, who looked dangerous after replacing Phil Burleigh, made a break on halfway and popped the ball to prop Greg Pleasants-Tate looming in support. The big man showed surprising pace to sprint over for a popular try under the posts. With Noakes' conversion the 31-7 score line suddenly looked comfortable for the Bay.
A try against the run of play from Samoan international Fa'atoina Autagavaia - after a Ranger break - left Northland trailing by 17 with 10 minutes remaining before another classy break and offload by Ranger put Wright over for his second.
With three tries, it was all to play for for the Taniwha in the final two minutes but they were unable to salvage any bonus points - that may well prove crucial when it comes to play-off time. It only gets harder from here on for the Taniwha, who face Canterbury on Friday, who beat 84-0 yesterday.
Scorers: Bay of Plenty Steamers 31 (Dan Goodwin 2, Carl Axtens, Greg Pleasants-Tate tries, Chris Noakes pen, 4 cons) Northland 19 (Matt Wright 2, Fa'atoina Autagavaia tries, Ash Moeke 2 cons). HT 10-7.