Even without their Black Ferns, Canterbury have held off a late charge from Bay of Plenty to maintain their unbeaten run through the Farah Palmer Cup and seal top seeding into the semi-finals.
The four-time champions, toppled by Waikato in last year's premiership final, have swept all their rivals en route to the playoffs, but had to work hard against the Volcanix, who came within a last-minute conversion of snatching a draw, eventually succumbing 33-31 at Tauranga.
Veteran international Renee Wickliffe barged over in the corner to bring the Bay within two points, but after the final siren, teenage first-five Kalyn Takitimu-Cook sent her sideline conversion under the crossbar.
Canterbury seemed well in control at 26-5 with halftime looming, after four tries, including a brace to winger Isabella Waterman, three converted by fullback Rosie Kelly.
Before the break, Takitimu-Cook cut the deficit with a converted try and when No.8 Pia Tapsell crossed after the restart, Bay had closed within striking distance.
Kelly's converted try in the 66th minute proved Canterbury's matchwinner, but Bay fullback Payton Takimoana grabbed her second of the game, before Wickcliffe's heroics made the seemingly impossible possible.
Canterbury have made a habit of winning close contests this season, with four of their six wins achieved by less than a converted try.
The result sets up a semi-final match-up between Canterbury and Wellington, while champions Waikato and Auckland shape up in the other elimination.
Meanwhile, North Harbour and Northland have progressed through to the championship semis with wins over Tasman and Taranaki respectively.
Canterbury 33 (Waterman 2, Muir, Mataele & Kelly tries; Kelly 4 conversions) Bay of Plenty 31 (Takimoana 2, Takitimu-Cook, Tapsell & Wickliffe tries; Takitimu-Cook 3 conversions)
Northland 31 (Nankivell, McGeorge, Erwin, Smith & Guest tries; Nankivell 3 conversions) Taranaki 19 (Blyde, Muggeridge & Munro-Smith tries; Muggeridge & Sim conversions)
