The Blue Jackets have six power-play goals in 67 opportunities, the lowest success rate in the NHL (8.9 percent).
"We had 10 chances on the power play, didn't score," Columbus coach John Tortorella said. "I am tired of dissecting our power play. We had 10 chances on the power play.
"Tonight's problem was we didn't finish. We developed a lot of scoring chances on it. This is my last night that I'm speaking on the power play because I'm tired of talking about it. Yeah, I'll leave it at that."
Gallagher made it 1-0 at 3:11 of the first period. He drove the right side and scored unassisted with a wrist shot from the right face-off circle. Gallagher leads the Canadiens with nine goals.
Drouin scored his first power-play goal, his first goal of any kind in nine games, to make it 2-0 on a slap shot from the left face-off circle at 8:10.
The goals came on Montreal's first two shots.
"That was big for us," Gallagher said. "You look at how this team's been having success, the biggest part of it has probably been [Bobrovsky], and for us to get a couple by him early, we knew it wasn't going to be easy and the rest of the way he made some pretty big saves as well. You know we got a couple by him, we were able to defend as good as we could, and obviously Price was back there to make a couple of saves when we needed it."