Adam Jecho’s second-period goal was the eventual winner as the Oil Kings held off Prince Albert with a 3-2 win on Wednesday night.
Edmonton has a 3-1 lead in the best-of-seven series.
Lukas Sawchyn and Gavin Hodnett also scored as the Oil Kings built an early 3-0 lead.
Rilen Kovacevic and Niall Crocker had goals in the final 10 minutes of play as the Raiders mounted a late comeback.
Game 5 of the first-round WHL playoff series will be played on Friday in Prince Albert.