Fourth-liners are typically the underappreciated, hard-hat workers of the NHL. They do whatever the team needs, most of which doesn’t show up in the stat sheet.

However, the blue-collar play of Shawn Thornton, Gregory Campbell and Daniel Paille is more than appreciated within the Bruins locker room.

For the past three seasons, the B’s Merlot line has consistently provided energy and physicality. And this postseason has been no different. But aside from a shorthanded goal from Paille in Game 3 against the Maple Leafs, the line has struggled to score.

That changed in the second period of Sunday’s 5-2 win over the New York Rangers with a goal from Campbell. Hours before the game, Thornton predicted his line would score, and he hopes the momentum carries over into tonight’s Game 3, with the B’s holding a 2-0 series lead.

“It helps. We want to try and take some pressure off the big lines. You can’t rely on them all the time,” Thornton said. “Obviously this time of year, your best players have to be your best players, but if we chip in every now and again, it helps out. We’ve been a little snake-bitten, too. We’ve had some chances. They just weren’t going in, so I was happy to see one go in for (Campbell) last game.”

The Bruins are at their best when all four lines are producing, as they did during the Stanley Cup run in 2011.

Campbell’s second-period goal Sunday was all hard work. The 6-foot center rushed to the net as Torey Krug fired a shot from the point. When the puck bounced off Dan Girardi’s skate, Campbell collected it and beat Henrik Lundqvist with the backhand to put the B’s up 2-1.