Claude Julien reunited Galchenyuk with his power play unit-mate, Jonathan Drouin, ahead of the game and you would be forgiven for confusing the head coach with a chemist based on the result.
"The three of them played well together," praised the Habs bench boss of a trio that also included Brendan Gallagher, who opened the scoring just 88 seconds after puck drop. "Even on the second goal, there was also quite the play from [Habs newcomer Mike] Reilly, so this line gave us some good offense tonight."
Asides from Galchenyuk's hat trick and 400th career game, there were some other exciting milestones reached in Brooklyn on Friday.
When Paul Byron put the Canadiens ahead 4-3 at 8:10 of the third, he scored what would end up being his first game-winner of the season.
With apologies to Byron, however, an even bigger milestone was reached by the young man who potted the Habs' insurance marker just 1:43 later. That man was Noah Juulsen, of course, and the milestone achieved was the first goal of his NHL career - in just his fifth NHL game.
"I think Lehky [Artturi Lehkonen] did all the work, pretty much," described Juulsen of the memorable marker. "He took it, he came up top and just passed it to me, and I just shot it. Luckily, it went in.
"I was just too in the game," Juulsen added of his rather low-key acknowledgement of the achievement. "The guys were all telling me I should've cellied a little harder, but I didn't even know it went in at first."