Without Fifita, Wellington trailed 10-8 at the break but stormed to a 20-10 lead with two tries in the opening four minutes of the second half. Canterbury forced their way back into the match with two tries, the last in the 77th minute from a lineout maul closing the gap to a single point, but could not quite finish the job.
This is unfamiliar territory for the red and blacks, who lost last year's final to Auckland having won nine of the previous 10 national provincial titles, but have now lost their first three games in 2019, a slump they haven't suffered the likes of in over 20 years.
They will not get a better opportunity to win next weekend however, hosting a Southland side on a 23-match losing streak.
Wellington 23 (Vince Aso, Du'Plessis Kirifi, Alex Fidow tries; Jackson Garden-Bachop con, 2 pens)
Canterbury 22 (Josh McKay, Mitchell Dunshea, Harry Allan tries; Brett Cameron 2 cons, pen)
HT: 8-10.