Magee and Austin Carroll each had a goal and an assist in regulation time for the Royals (19-14-2), who trailed 3-0 heading into the third period, while Jamie Crooks scored the other.
Chase Witala scored twice and added an assist for the Cougars (12-19-5) and Colin Jacobs had a goal and an assist.
Patrik Polivka started in goal for Victoria but was pulled after allowing three goals on 10 shots through 26 minutes of play. Coleman Vollrath earned the win after stopping all 10 shots he faced in relief while Mac Engel made 41 saves in a losing cause.
Victoria went 1 for 6 on the power play while Prince George scored twice on six chances with the man advantage.