Canterbury, who won the toss and batted first, scored 296 for four with solid contributions from their top six batsmen starting with openers Rob Nicol and Michael Papps who shared in a 129-run partnership for the first wicket.
In reply, Otago could only muster 197 all out in 46.1 overs.
Papps reached 63 before departing leg before wicket to spinner Nathan and was quickly joined in the shed by Nicol, 58, four runs later.
But Peter Fulton, who scored a century in their first round two-wicket loss to Central Districts, picked up from where he left off to score 87 while sharing partnerships of 66 with Dean Brownlie for the third wicket and 67 for the fourth wicket with Shanan Stewart who was 27 not out.
Andy Ellis joined Stewart for a fiery finish to the innings, scoring 23 runs of just nine balls.
Otago, who beat Wellington by four wickets, struggled to contain Canterbury in the field with Neil Wagner the best of their bowlers with two for 70.
With Canterbury bowlers Hamish Bennett and Ellis in good form, Otago struggled to put runs on the board though Michael Bracewell scored 68 and skipper Craig Cumming 46.
Wicketkeeper Derek de Boorder contributed another 32 but no one else stood up to the pressure exerted by Canterbury in the field.
Bennett was especially economical with three for 24 while Ellis had figures of two for 36.