Tyler King had a goal and an assist for Kootenay (24-22-1), and Levi Cable rounded out the attack with an empty-net goal at 19:42 of the third period.
Brett Pollock struck twice and added a helper for the Oil Kings (22-19-6). Ben Carroll also scored.
Ice goaltender Wyatt Hoflin made 28 saves for the win. Edmonton's Tristan Jarry stopped 34-of-38 shots in the losing effort.
Kootenay was 2 for 3 on the power play while the Oil Kings failed to take advantage of three opportunities with the man advantage.