The Bulls, who are aiming to make their first final in four years, trailed 12-0 early before scoring six consecutive tries to take control of the game.
Sleight of hand from Arona and some charging runs from 17-year-old forward Caius Fa'atili were standout facets of the match.
Fa'atili appeared to suffer a knee injury of late which will have the Bulls sweating on his fitness.
It was the only blemish on a stellar day for the Canterbury team.
The Bulls will play Waikato at Hamilton's FMG Stadium on Sunday in their round two clash before playing their lone home game against the Counties Manukau Stingrays at Nga Puna Wai on September 29 at 1pm.