Third-period penalties by Alexander Semin, Dale Weise and Nathan Beaulieu cost the Canadiens the lead, but it would be a Taylor Beck penalty for goaltender interference that cost the Islanders the game.
Alex Galchenyuk, who couldn't buy a goal for the first 56 minutes of the game (and several games before that) finally found the back of the net with a shot that makes you wonder how he doesn't score more often. The powerplay goal with 3:29 left in the third period gave the Canadiens the 3-2 lead they would not relinquish.
After a shaky game on Friday, and a shaky first period that saw him more active and out of position than usual, Carey Price came into his own and made several big stops among his 21 on the night.
The Islanders opened the scoring with 1:19 left in the first period when John Tavares put one in the open net behind Price.
The Canadiens responded nicely in the second period with David Desharnais scoring a powerplay goal midway through the period to tie the game at one, and then Tomas Fleischmann scored a short-handed goal on a beautiful shot on a 2-on-0 break. Both players scored their seventh goal of the season.
Anders Lee scored a goal right after Weise's penalty expired in the third period with 8:07 left setting the table for Galchenyuk's winner.
The real story in this one may end up being the injury to Brendan Gallagher. Gallagher took a shot to the left hand in the second period. He is now out indefinitely with two fractures that require surgery.
Semin took over in his place on the line with Tomas Plekanec and Max Pacioretty, but played only 1:08 in the third period, and his only time on ice after the last-period penalty was the skate to the bench once it was over.
Michel Therrien did show a pattern of rolling all four lines throughout the game as every center had a faceoff against each Islanders center throughout the game. Plekanec had eight each against Tavares and Frans Nielsen. It's an interesting strategy and it adds importance to how the lineup shakes out with Gallagher's long-term prognosis.
Unless Devante Smith-Pelly is ready to go, you can probably expect Bud Holloway to make his NHL debut on Wednesday, but it remains to be seen who will fill the right side of the top line.
Sven Andrighetto's NHL season debut went as well as you could hope for, and the Gallagher injury forced Therrien to lean more on Lars Eller and Galchenyuk. Andrighetto was an exceptional +14 in even-strength shot-attempt differential, with 81.82% Corsi-for percentage; good enough to lead all forwards. That line (along with the blue-line pair of Tom Gilbert and Greg Pateryn) were the Canadiens best five-man unit in terms of possession.
Galchenyuk, in a post-game interview with RDS's Marc Denis, said he could have had four goals on the night. For now, after its performance in the last two games, that line seems to be one that cannot be touched.
With the win, the Canadiens move back into the top spot in the Eastern Conference, leap-frogging the Metropolitan Division leader with the improvement to a 16-4-2 record. Their next game is Wednesday night at Madison Square Garden against King Henrik and the dethroned New York Rangers.