Kamloops outshot host Kelowna 18-3 in the opening 20 minutes and took a three-goal lead into the first intermission, en route to a 4-2 victory in Western Hockey League playoff action.
Brendan Ranford scored twice in the first period for the Blazers to go along with Aaron Macklin's first-career post-season goal.
Chase Souto scored an insurance goal for Kamloops midway through the third period.
Henrik Nyberg and Cole Linaker responded in the second period for the Rockets, who made their best attempt at a comeback.
Cole Cheveldave made 21 saves for the win as Jordan Cooke stopped 29-of-33 shots in defeat.
Kamloops went 2 for 4 on the power play while Kelowna failed to score on its only chance with the man advantage.
Game 2 is scheduled for Sunday when the Rockets host the Blazers at Prospera Place.