The Canterbury side was too big and physical for the Whalers, running in 10 tries to two.
Canterbury A coach Shane Endacott said he was pleased with his side's effort and it was a bonus to win by such a large score.
Whalers coach David Reedy said Otago was beaten by a "battle-hardened" team, and paid the price for some weak defence and pushing too many passes.
The first half saw Canterbury camp inside Whalers territory, scoring five tries to one in a classy display.
The Whalers were forced to make too many tackles, and when they had possession and made a break into Canterbury's half, silly passes went to ground and the ball was turned over.
Canterbury was able to capitalise on the Whalers' mistakes, and on the back of a dominant forward display it held a 24-6 lead at halftime.
The second half carried on from the first with Canterbury jumping out to a 34-6 lead before Whalers winger Alan Manu scored in the corner to reduce the deficit.
But that was all the Whalers could muster as Canterbury scored three tries in the final 20 minutes to finish off a fine performance.
The Canterbury halves pairing of standoff Tim Rangihuna and halfback Sean Scott were dynamic, while lock Aga Fiso and second-rower Vince Brown had strong games in an impressive forward pack.
Whalers second rower Shane Unahi was the pick of his team, with some strong tackling and good runs.
In the Dunedin spring competition, the South Pacific Raiders beat Pirates 20-18 at Hancock Park on Saturday.
Both teams scored four tries, but Pirates rued a missed conversion right on fulltime that would have given it the draw after the scores were locked up 6-6 at halftime.
Three late second-half tries gave University a 22-18 win over the Harbour Hawks. The students outscored the Hawks five tries to three after leading 8-6 at halftime. The win means University remains undefeated, and it was the Hawks' first loss in two years in the spring competition.
The South City Dragonz won a close game against the Kia Toa Tigers 24-20.
The Dragonz scored five tries to four after the teams were tied 10-10 at halftime.
In a one-sided match, the Kaikorai Silverbacks recorded their first win of the season when they beat the Dragonz B side 46-12.
The Silverbacks held a handy 28-8 lead at halftime and were never in danger of being run down, outscoring Dragonz B 18-4 in the second half.
- Jack Salter and Tim McCauley
