Cole Wedman and Mitch Holmberg scored for the Chiefs (8-2-0), who trailed 2-0 after 40 minutes of play.
Holmberg also had an assist and leads the WHL in scoring with 12 goals and 25 points in 10 games.
Greg Chase and Zane Jones supplied the offence for the Hitmen (5-3-1), who have earned at least one point in three straight contests.
Eric Williams stopped 26 shots in regulation and overtime, plus all six shooters in the shootout, for the victory. Chris Driedger made 28 saves in defeat.
Neither club could produce on the power play as Spokane went 0 for 5 while Calgary went 0 for 3.
ICE 2 RAIDERS 0
CRANBROOK, B.C — Mackenzie Skapski made 30 saves for the shutout to lead Kootenay.
After two scoreless periods, Jaedon Descheneau scored and Luke Philp added one into an empty net for the Ice (5-4-1).
Nick McBride stopped 30 shots in net for Prince Albert (6-4-1).