Winterhawks' forward Adam Schoenborn battles Rockets' defenceman Cole Martin along the boards in WHL playoff action Wednesday in Portland.

(VIDEO) Rockets pushed to edge in Western Conference final

Portland downs Kelowna in Game 4 Wednesday to take 3-1 lead in WHL semifinal series

Losing just once in the next three games isn’t an option if the Kelowna Rockets have designs on prolonging their 2013-14 season.

Nic Petan scored three power play goals Wednesday night, leading the hometown Portland Winterhawks to a 5-1 win over the Rockets and a 3-1 lead in the best-of-seven Western Conference final series.

Game 5, a must-win for Kelowna, is set for Friday night at Prospera Place.

The Rockets opened the scoring for the third time in the series, as rookie Nick Merkley connected at 13:28 of the first period for his fourth goal and team-leading 17th point of the playoffs.

But the Rockets ran into penalty trouble soon after, and it was all Portland the rest of the way.

Petan evened the score on a power play at 18:58 of the opening period, then scored twice more in the second with the man advantage as the Winterhawks tallied five unanswered goals.

Oliver Bjorkstrand added a shorthanded marker in the second period, while Paul Bittner scored into an empty net to round out the scoring, as the Winterhawks outshot Kelowna 36-32.

From a Kelowna perspective, it was a much better effort than the previous night’s 4-3 overtime loss when the Rockets were outshot 65-33.

Still, Rockets assistant coach Dan Lambert said far too few Rockets have come to play so far in the series to give his team a legitimate chance to win.

“When you play an elite team like Portland, you need everybody to be really good,” Lambert told AM 1150. “Right now, we have a lot of passengers.

“When you play against a team like Portland that has the puck a lot and makes plays, it’s hard work, and sometimes guys choose to take the easy way out. There’s a collective bunch of guys that need to be better.”

As for facing elimination on Friday night, Lambert said the Rockets need to be fully committed to the task, much like their 5-4 victory in the series opener.

“(Head coach) Ryan (Huska) and I wanted our team to play the right way tonight and we felt that if at least we got going that way and feeling good about ourselves, then good things would happen,” Lambert said. “We did that in the first period, we played the right way. We need to do that for 60 minutes on Friday night.”