The Islanders could not afford a fifth straight loss on Saturday night.

Not when they held such a precarious position in the Eastern Conference standings, with the Penguins holding games in hand while the Sabres and Red Wings both were creeping up. Not after a morale-sapping third-period collapse against the Wild on Thursday. Not with the tanking, hapless Canadiens their opponent at UBS Arena.

Winning was a bare minimum, and losing would have been tantamount to a fire alarm for a group that thinks itself good enough to make it back to the playoffs.

Even after beating the Canadiens 2-1, however, the pressure is nowhere near off the Islanders, who still face four pivotal games against four playoff contenders over the next seven days — but with their record at 23-18-3, they can at least breathe a little bit easier.

“When we’re having success,” captain Anders Lee said. “That’s what it looks like.”

The message Saturday morning from coach Lane Lambert, on the back of the messy loss Thursday, was simple: Shoot the puck and hit the net.

“If you miss the net, you can’t score,” Lambert said. “My dad told me that when I was 5 years old.”

Eight hours later, the Islanders hit the ice like a team that had gotten the message. They put their usual first-period woes aside and jumped all over Montreal from the outset. The Islanders got pucks deep. They forechecked. And most important, they let loose with ease, beating goaltender Sam Montembeault twice inside of seven minutes to set the tone for a victory on a night when anything less would not have sufficed.

Casey Cizikas opened the scoring by tipping in a point shot from Noah Dobson at 2:25 of the first period. That was followed by Anthony Beauvillier jumping on Scott Mayfield’s rebound to break an eight-game scoreless drought of his own less than four minutes later.

“Put ourselves in a good position to control the game,” Cizikas said. “I thought we did that with the way we started. We came out hot, we came out heavy, we played in their end, which is the biggest thing. It’s something we can build off.”

It was the first time since Dec. 16 at Arizona that the Islanders led 2-0 in a first period. And unlike that night in Tempe, it was not followed by a second period in which they fell apart at the seams.

Granted, the dominant start they displayed did not continue past the first 10 minutes. They did not pull away from Montreal, and at times they relied on goalie Ilya Sorokin, who finished with 22 saves in his 10th start out of 11 games, to bail them out.

The Canadiens made them sweat. Nick Suzuki made it 2-1 at the 9:56 mark of the third, skating by Mayfield before beating Sorokin.

The Islanders, though, hung on, after Montreal failed to pull Montembeault until there was 1:07 left in the game — at least 30 seconds too late. And with the added bonus of the Penguins losing to the Hurricanes, the Islanders hopped Pittsburgh for the last wild-card spot in the East.

“I liked our response when they scored,” Lambert said. “I thought we kept pushing forward.”

Cizikas afterward talked of the players holding each other accountable and challenging each other over the last 48 hours, a message that, at least on Saturday, seemed to work.

“We know what type of team we have in here,” Cizikas said. “And we know what we can do when we work as a group.”

“Holding guys to a standard that we believe in,” Lee said, describing the conversations among players between Thursday and Saturday. “We believe in this group, we believe in one another and sticking with each other, having each other’s backs, demanding the best from the guy sitting next to you and yourself. It’s an accountability thing.”

This was the gotta-have-it game of the homestand, and the real test will come in the four games the Islanders play over the next seven days.

But they did win, and that was a necessary first step.