The goal was waved off for goaltender interference because Jeff Petry was ruled to have pushed Shore into Koskinen, but Canadiens coach Claude Julien challenged, and the call was overturned after video review.
"You're always a little nervous, there are no guarantees whether you're going to win that or not," Julien said. "Had we lost that, we were starting more or less the third period shorthanded … We could be ahead 2-0 or we could start the third period up 1-0 and having to kill 1:50 of an Edmonton power play. There was a bit of a risk, but I really felt confident that we can win this challenge."
Artturi Lehkonen scored shorthanded on a 2-on-1 at 12:15 of the third period to make it 3-0.
Edmonton had the No. 1 power play in the NHL last season but was 0-for-10 in the two games against Montreal.
"We were moving it around pretty well and getting some good looks, but when teams are pressuring you like that and things aren't clicking, maybe we need to shoot the puck more, get rebounds and create chaos," Oilers forward Ryan Nugent-Hopkins said. "... It was one of those games that was frustrating. The power play had tons of looks and just couldn't find one."
Shore scored shorthanded at 17:51 to make it 3-1, stripping Jonathan Drouin of the puck at the Canadiens blue line and scoring on a breakaway.
"We were more competitive, but I'd still like to see our puck game improve," Edmonton coach Dave Tippett said. "Competitive is what we're looking for. To defend better, you've got to be competitive first, then you've got to be able to move the puck. We were better on the competitive end of it."