BOSTON — The Islanders scored one win over a top team in the NHL on Friday. They couldn’t score another this time around. 

They can comfort themselves thanks to an overtime point, but the Islanders will head out west with the momentum from Friday night’s win over the Devils having evaporated into a two-game losing streak after the Bruins defeated them 4-3 on Tuesday night at TD Garden following a shootout. David Pastrnak notched the winner for Boston, with Josh Bailey’s final attempt missing the net high for the Islanders. 

“It felt like a playoff game,” Mathew Barzal said. “That’s really it. It’s a huge point to get.” 

The Islanders (17-12-1) weren’t overwhelmed by Boston’s speed, and had the better of the game at five-on-five, but their power play was their undoing. Not only did they fail to generate much offense at five-on-four, but they gave up a go-ahead shorthanded goal on Derek Forbort’s wrist shot at 18:28 of the second. That put the Bruins up 3-2 and helped turn the tide of a game that hung in a nearly even balance for much of the night. 

Casey Cizikas tied the game at three for the Islanders with a wraparound attempt that went off Forbort’s skate and in at 4:40 of the third. They couldn’t parlay that momentum into a win, but they did exit feeling good about earning a point in a building where no opposing team has beaten the Bruins in regulation this season. 

“That’s a big point for us,” Noah Dobson said. “It’s a good building block for this road trip.” 

The Bruins opened the scoring with a 19-second flurry in the first period, both goals courtesy of Jake DeBrusk. First, on the power play after Zach Parise was called for goaltender interference, DeBrusk deflected Pastrnak’s shot past Semyon Varlamov at 6:48. Then, at 7:07, he streaked up the ice off the rush to score a second time, prompting Islanders coach Lane Lambert to use his timeout. 

“It was a little bit calming,” Lambert said. “I thought we were playing well to that point. That was the message, just keep going. There’s a lot of hockey left.” 

The message hit home, as the Islanders soon got their footing under them. Bailey cut the deficit in half, deflecting Dobson’s shot into the net to make it 2-1 at 11:00 of the first. Dobson tied the game at two with a missile of a one-timer from the point at the 11:43 mark of the second. 

When A.J. Greer was called for roughing at 16:39 of the second, all the momentum looked to be with the Islanders. But less than two minutes later, that had slipped away in the wake of Forbort’s goal. 

The Islanders are still missing two key players from their top nine in Kyle Palmieri and Anthony Beauvillier, and on Tuesday, Cal Clutterbuck skated with the second line to accommodate Hudson Fasching on the fourth. That, combined with this part of the schedule being somewhat grueling, makes treading water an acceptable outcome, and it’s tough to knock the Islanders when they earned a point after going down 2-0 against the Bruins. 

“I thought we were focused,” Lambert said. “I thought we did what we wanted to do and we played fast. We continue to do that, we’ll have success more often than not.” 

That 19-second stretch in the first period stands as a key moment of lapsed concentration that might have turned the game. So does the shorthanded goal. And the Isles need every point they can get as the Rangers and Penguins rebound from slow starts and get back into the playoff chase. 

They got one on Tuesday. But another sure would have been nice.