NEW YORK — Maybe James van Riemsdyk should have blocked it. Maybe Brian Elliott should have saved it. The laser that Ryan Pulock blew past everybody was worth one game-winning goal on the stat sheet and two very important points in the standings.

Blocked shots played big parts in the Flyers’ most recent wins. On Tuesday night, that big defensive play when they needed it never materialized.

“It’s frustrating,” Elliott said. “The guys battled back to try to secure at least a point. For it to end like that ... .”

The Flyers nearly were run out of the Barclays Center with a sloppy first period that saw the Islanders jump to a 3-0 lead, thanks to several defensive breakdowns. The most-glaring was Phil Myers and Travis Sanheim being caught on a rush that resulted in Scott Laughton being the only defender on a two-on-one.

The result was as predictable as the wide-open net into which Matt Martin scored.

It took the Flyers until 92 seconds remained to finally get it tied. It would have been a terrific point to get, even had they lost in overtime or a shootout.

“The first period probably cost us the game,” said Sean Couturier, whose goal in the waning minutes tied it.

“Heck of an effort battling back,” defenseman Matt Niskanen said. “We had a pretty awful first, a pretty darn good second two periods, then we just [dribbled] one down our leg at the end.”

Colorful metaphors aside, this was the third game in the last four in which the Flyers have given up the first goal. It’s been a problem in spurts during this otherwise resurgent season. Philadelphia entered Tuesday’s games minus-14 in first-period goal differential, last in the league.

Their third-period differential was plus-21, tops in the league. Go figure.

“We didn’t come ready to play,” Travis Konecny said. “[But] the bench was pretty confident the whole game ... trusting that the process and system would pay off in the end, which it almost did there.”

They just could have used one more play.

“Unfortunately they got that fourth goal where we need either a save or a blocked shot,” coach Alain Vigneault said. “I talked about the importance [Monday] of blocked shots. We had an opportunity to get one there and we didn’t. We lost a big point tonight.”