The Bulls will now face the Akarana Falcons in the decider, a team they beat 28-18 at Auckland's Pulman Park to open their campaign three weeks ago.
The Bulls maintained their unbeaten season thanks to a late try from co-captain Tevin Arona.
The last time Christchurch hosted a final was in 2009 when the Bulls beat Auckland 26-20 at Rugby League Park.
It is the first time since 2015 the Bulls will play in a decider.
The final will be played on Saturday with times yet to be confirmed by the NZRL
The Otago Whalers and Wellington Orcas will play in the curtain-raiser.
Over at Rangiora's Mainpower Oval, Canterbury Country can thank Jack Boyle for getting bragging rights on their Metro counterparts in a preseason cricket game.
Boyle hit 119 with the bat and then took five for 28 with the ball as Canterbury Country defended their total of 244 for six to win by 32 runs.
The club season gets underway on Saturday.
