Tasman will come up against Canterbury semifinals of the ITM Cup Premiership after being upset by Counties-Manukau to round out the regular season.
The Makos needed two points to take top spot in the top tier but Counties mounted a furious resistance in the final minutes to win 21-16 and hand Taranaki home advantage throughout the playoffs.
The Steelers had nothing but pride to play for, after Auckland's victory shut them out of the playoff picture, but they could certainly be proud of their efforts at Lansdowne Park.
Having dominated large patches of the game but unable to separate themselves from their hosts, Counties looked like they would walk away unlucky losers when Tasman spent the final few minutes camped on the line. But, for phase after phase, the Steelers defence held firm, repelling an attack that had several chances to reset through repeated penalties.
Tasman's punishment for failing to break through comes in the form of a semifinal encounter with their big brother. Tasman will take confidence into the clash after crushing Canterbury a week ago in Christchurch but the Makos will know their Super Rugby franchise partners are a different proposition come finals time.