The first spell was all-action, with three tries, two yellow cards and two Steelers forwards crocked.
Counties Manukau had the majority of the ball and made much of the play, but too often they coughed up the ball or made a poor decision on attack. No 8 Jordan Taufua was at his explosive best, making several bursts and winning lineout ball, which was crucial when captain Jimmy Tupou exited with a knee niggle. Second five Cardiff Vaega made hay in the backs, punching holes, and taking advantage of the fact that the Makos were reduced to 13 men when David Havili and Robbie Malneek, in his 100th match as a Makos original, were binned.
Halfback Richard Judd scored the Steelers' opening try, from a simple 8-9 scrum move. That followed a try against the run of play by the Makos from centre Kieron Fonotia, who got on the outside of his man. Fonotia was absent for the loss to Auckland last Sunday, and it showed.
The Steelers travel to Hamilton next Friday to face neighbours Waikato, while Tasman have a top of the Premiership clash with Canterbury in Nelson next Saturday.
In the curtainraiser, the Counties Manukau Heat dispatched the Otago Spirit 55-24 to stay firmly in the Women's Provincial Championship semifinals hunt.
Counties Manukau 42 (R. Judd, C. Vaega, S. Nabou, P. Cowley, O. Auva'a tries; P. Francis 2 con, 3 pen, W. Walker 2 con)
Tasman 33 (K. Fonotia, M. Banks, B. Guyton tries; Banks 2 con, 2 pen, D. Havili con, 2 pen)
Halftime: 21-13