Auckland is on the cusp of relegation from the NPC Premiership following another ragged performance in losing 31-18 to Tasman in Nelson.
The home side's dominant win guarantees them a play-off berth and means the semi-finalists have been found one round early.
They will join Taranaki, Canterbury and North Harbour regardless of the results in the final round next weekend.
More interest will focus on the fate of Auckland, the most successful union in NPC history with 16 titles, whose final match is against powerhouses Canterbury.
They are locked in a dogfight with another proud province, Waikato, to avoid dropping to the second-tier Championship.