The Eagles scored three power-play goals in the second period from Jeffrey Stewart (2) and Jackson Ross to give the hosts a commanding 4-1 lead after 40 minutes.
Ben Brar scored the lone goal in defeat for the Spruce Kings on a 5-on-3 man advantage.
The Mainland Division series lead now belongs to the Eagles at 2-1 with game 4 set for Tuesday.
Surrey ended up with a 1-0 advantage after the opening period, Prince George never led in the contest.
John Wesley added another late in the third.
Evan DeBrouwer gave up five goals on 38 shots in defeat.
Mario Cavaliere picked up his second consecutive win in net for the Eagles making 30 saves.
Game 5 is set for Thursday at 7 p.m. from the Rolling Mix Concrete Arena.