They will face the Highlanders in the final at Eden Park at 7.05pm on Saturday 19 June after the southerners took out the Brumbies 33-12 in Canberra on Friday night.
The positions were determined by results in the last round (round 5) that ultimately saw three teams - the Blues, Highlanders and the Crusaders - all finish on 23 points at the top of the ladder.
The table positions were decided on a total points for and against as all three teams finished with five wins. The Blues secured top spot with a points difference of 119 compared to 103 for the Highlanders and 97 for the Crusaders.
Tickets are on sale from 9am on Sunday 13 June at Ticket Master.