Austin Pratt forced overtime with 41 seconds left in the third period on his eighth goal of the season.
This came just 42 seconds after Josh Tarzwell gave the Rebels a 2-1 lead.
Arshdeep Bains scored the game-winner 48 seconds into the extra frame. Chase Leslie also scored for the Rebels.
Zach Smith had the Pats other goal, his first WHL tally. The rookie now has two points (1-1) in three career games.
Max Paddock stopped 24-of-27 shots for the Pats, while Byron Fancy stopped 25-of-27 for the Rebels.
The Pats host the Swift Current Broncos on Friday. Game time is 7 p.m.