BOSTON – Shawn Thornton returned Wednesday night from a three-game layoff caused by a 40-stitch gash in his forehead to help the Boston Bruins’ fourth line spark a 3-2 victory against the New York Islanders.

Thornton, sidelined after being cut by a skate, started the Bruins to victory with his career-high 10th goal with a tenth of a second left in the first period.

Then his linemates made their big plays — a goal by Gregory Campbell made it 3-1 midway through the second period and a block by center Daniel Paille, who threw his body in front of the puck in the final minute.

“It felt good to get back in there,” Thornton said. “Our line did a heck of a job.”

Thy did better than the rest of the Bruins.

“We weren’t very sharp,” Coach Claude Julien said. “Our best players certainly didn’t make a difference.”

Dennis Seidenberg and Campbell scored in a 1:18 span in the second and Boston closed within two points of the second playoff spot in the Eastern Conference.

The Bruins, who have clinched the Northeast Division, have 101 points. The Philadelphia Flyers have 103. Both teams have two regular-season games left.

“I don’t think we really start the season with a point total in mind,” Campbell said. “It’s just to win the division and do the best we can and get the highest seed we can.”

Boston, which has a 6-2-1 record in its last nine games, will finish at home against Ottawa on Saturday and at New Jersey on Sunday.

New York, already eliminated from playoff contention, lost for the fifth time in six games.

“There were a couple of bad bounces in the second period,” Islanders goalie Rick DiPietro said, “but overall I thought we played well.”

Michael Grabner scored both goals for New York, making it 1-1, then cutting the deficit to 3-2. He has 33 goals, two more than Logan Couture of San Jose for the rookie lead.

“It’s nice to get two goals but it would have been nicer if we got a win,” Grabner said. “I just go out there and try to score. That’s what I was drafted to do.”

Thornton gave Boston a 1-0 lead after Campbell passed the puck from the right corner of the crease and he lifted it over DiPietro from the left of the crease.

“It was killing him missing those three games but he was healing,” Paille said. “To have him back and get a goal that quick, I’m sure he’s excited.”

The Islanders tied it just over a minute after Bruins goalie Tim Thomas stopped three close shots in a five-second span.

“He’s a tremendous goaltender,” Islanders Coach Jack Capuano said. “He’s obviously the best in the league.”

Grabner tied it on a power play with 3:24 gone in the second. But Boston took a 3-1 lead on those two goals over a minute apart.

And they stayed ahead just two days after blowing a 3-2 lead to the New York Rangers.

“The consensus after the first period (Wednesday) was that we were just playing OK,” Campbell said. “For us to come out and score a couple of goals and get on top, and find ourselves in the same situation we were in Monday night, and have another crack on that and to keep that lead, that was good.”