Olivier Bjorkstrand and Taylor Leier each had a goal and an assist for Portland in a 3-1 win over the Edmonton Oil Kings on Tuesday.
Ty Rattie also scored as the Winterhawks took a 2-1 lead in the championship series after Portland had to settle for a split at home.
Michael St. Croix had the lone goal for Edmonton.
"I thought it was a good effort by our team," said Portland Winterhawks head coach Travis Green. "It was a good road win. Obviously getting a lead like that is important against a team like (Edmonton). They came hard and we weathered the storm a bit and our veteran guys were really good.
"We don't dwell on big wins or big losses. We still have to come to the rink the next game and put a good effort out on the ice, and hopefully (Wednesday) we can have another solid effort."
Portland opened the scoring at 4:39 of the first after Bjorkstrand eluded Edmonton defender Keegan Lowe along the outside to set up the feed in front to a wide-open Leier.
Rattie doubled the Winterhawks lead with his 17th of the post-season, finishing off an odd-man rush with Nicolas Petan with a wrist shot through Laurent Brossoit's five-hole at 8:14 of the opening period.
Bjorkstrand sent Portland into the second period with a 3-0 lead after tucking a backhand up high from in tight at 15:48 into the blocker corner.
"Obviously if we could take that first period and throw it out the window, we'd be in the game a bit more," said Edmonton head coach Derek Laxdal. "We didn't come out with a lot of urgency. Second and third period we got it going a bit. But we can't spot Portland a lead like we have. They're too good of a hockey club.
"From the time you get into the arena, you have to be ready to play. These guys know how to respond, they have all year."
St. Croix put Edmonton on the board at 9:13 of the second, burying a cross-crease feed from Dylan Wruck in behind Portland netminder Mac Carruth.
Edmonton nearly made it a one-goal game just moments later as Curtis Lazar broke in alone, but Carruth stretched out with the right pad to keep the Winterhawks ahead 3-1 heading into what would be a scoreless third period.
"We have to get more pucks through and we have to be ready when they do get through," added Edmonton winger T.J. Foster. "We had a couple chances on rebounds where we didn't bury it. He takes away the lower half, we have to get it upstairs."
Carruth stopped 38 shots in net for Portland, while Brossoit turned aside 24 pucks for Edmonton.
Neither team struck on the power play as Portland held four opportunities with the man advantage and Edmonton earned one.
The series resumes for Game 4 at Rexall Place on Wednesday night.