The teams exchanged four goals in a five minute span early in the first period, with two from St. Croix, another for Edmonton from Curtis Lazar, and Luke Philps for Kootenay.
Luke Bertolucci made it 4-1 Oil Kings in the second period on a wraparound.
Griffin Reinhart's power play goal made it 5-1 in the third period, and the Ice changed goalies with Wyatt Hoflin replacing Mackenzie Skapski.
Trevor Cheek scored on Edmonton's first shot on the new goalie and Cole Benson later made it 7-1.
Laurent Brossoit made 24 saves for Edmonton while Skapski made 27 saves, and Hoflin five for Kootenay.
The Oil Kings connected on their lone power play opportunity, while the Ice was 0 for 3.