While the Rangers’ stars let them down in Game 7 on Monday night, it was a group of Devils unsung heroes who were the difference in a 4-0 New Jersey victory.

First, it was fourth-line center Michael McLeod scoring the Devils’ first goal midway through the second period on a marvelous assist by veteran Ondrej Palat with the Rangers on a power play.

Palat outworked Rangers top defenseman Adam Fox for the puck near the blue line and skated toward goalie Igor Shesterkin, drawing Rangers center Mika Zibanejad toward him.

Then he deftly slid the puck underneath Zibanejad, who’d given up his body, and onto the stick of McLeod.

McLeod, not a goal scorer, looked like one on the play as he got in front of Shesterkin and froze the all-world netminder with a hesitation move that allowed him to get around his outstretched pad and flip a backhander into the net for the 1-0 lead with 10:07 remaining in the period.

“That’s what the playoffs are all about; there is always that unsung hero, that guy that scores that big goal,’’ Devils coach Lindy Ruff said. “I mean, what a goal by Michael. Not only taking big draws most of the night, but to score that goal. Their goalie sold out. Maybe another player may have tried to shoot it, but he hung onto it and put it in the empty net.

“I’m happy for him, because he takes a lot of pride in his faceoffs, and for him to get a big goal was incredible for the team.’’

Devils captain Nico Hischier raved about the goal as the play “that got us going.’’

“What an effort from Pally and what a finish by Mikey,’’ Hischier said.

“I was just trying to pressure Fox and get the puck,’’ Palat said. “Then I saw I had a little more space and Mikey was there and I just tried to pass it. What a play by Mikey. What patience. What a player. Great goal.’’

McLeod, who scored just four goals all season, gets playing time because he’s an excellent penalty-killer and a faceoff wizard, not because he’s a goal scorer.

The last goal McLeod scored this season came on Jan. 4 at Detroit.

He has 19 goals in 242 career regular-season games.

“Pally made a great steal and I just went to the net,’’ McLoud said. “It felt great. It’s been a little drought and it was nice to get on the board.’’

For Palat, this was his 145th-career playoff game, and he now has 99 points in the postseason on 50 goals and 49 assists.

The Devils’ second goal, which came with 4:21 remaining in the second period, was almost as unlikely as the first one.

This time it was Tomas Tatar on a play completely created by defenseman John Marino.

Marino worked his way in toward Shesterkin and shot the puck wide left, but he kept the play alive by maintaining possession of the puck and flicking a backhand pass from behind the Rangers’ net toward Tatar, who beat Shesterkin up high for a 2-0 lead.

Before that play, neither Tatar, who had 20 goals in the regular season, nor Marino, had produced a single point in the series.

The Rangers were unable to come back from the deflating deficit and their season ended abruptly while the Devils move on to the second round against Carolina.

For Ruff, this was the fifth Game 7 of his coaching career and the first one he’s won.

Ruff entered the night 0-4 in Game 7s as the Buffalo Sabres and Dallas Stars coach.

This was his first as the Devils coach, and it was a memorable one, thanks to the unlikely heroes on his bench.