Philippe Halley scored five minutes into overtime on Friday night to give the Gatineau Olympiques a series-clinching victory over the Rimouski Oceanic at the Robert Guertin Centre.
Halley's second goal of the playoffs secured a 4-3 win in Game 5 of the first-round QMJHL series.
Christian Ouellet, with two, and Mitchell Porowski scored in regulation for the fifth-seeded Olympiques, who came through in the clutch with three of their four opening-round victories coming in overtime.
Gatineau's second-round, quarter-final opponent will be the No. 4-seeded Drummondville Voltigeurs, who are coming off a sweep of the Chicoutimi Sagueneens.