Max Sasson and Aatu Raty added second-period markers for the Canucks, who took a 6-1 lead into the break.
Hughes added a seventh for Vancouver 8:26 into the third period, converting on an odd-man setup from Boeser.
Sasson rounded out the scoring with a short-handed tally in the final minute.
Ivan Prosvetov got the start in goal for Calgary and made 14 saves, his best coming off a Drew O’Connor breakaway early in the first period.
Logan Cooley played the final 28-and-a-half minutes of the contest and made four stops, notably stoning Pettersson on a second-period penalty shot.
