NHL

Islanders flattened by Flyers, 7-0

A sellout crowd filled Nassau Coliseum to see the suddenly resurgent Islanders — who were on a two-game win streak thanks to triumphs over the hated Rangers and rival Devils — and wunderkind John Tavares, the freshly-named NHL’s First Star of the Week.

It’s a shame the Islanders had to ruin all the positive vibes on Presidents’ Day with an effort — by far their worst of the lockout-shortened season — that reminded everyone why expectations were so low to begin with.

They fell behind just 26 seconds into the contest, and the afternoon only grew unbearably worse in a jarring 7-0 loss to the middling Flyers — the worst home shellacking in Islanders history.

“To play like that is just unacceptable,” Tavares said. “We can’t have efforts like that.”

If it were a boxing match, the fight would have been stopped in the second period, and saved the Islanders’ faithful their vocal cords.

They spent large portions of the rout groaning and booing. There was even a brief “DP” chant for beleaguered backup goaltender Rick DiPietro after Evgeni Nabokov, left out on an island much of the afternoon, was beaten for the third of what would be seven times.

“He’s been playing great for us,” defenseman Mark Streit said of Nabokov. “We just didn’t help him enough and they scored way too many goals.”

Danny Briere notched a hat trick and Claude Giroux scored twice in the onslaught for the Flyers (7-9-1, 15 points).

Even the Islanders’ (6-8-1, 13 points) special teams, ranked among the best in the league, struggled. They whiffed on five power-play opportunities, including two minutes worth of 5-on-3, and gave up two power-play goals.

“They were the hungrier team,” Islanders coach Jack Capuano said. “At the end of the day, they won the wall battles, they won the 50-50 puck battles, and physically they manhandled us. That, to me, is controllable. That’s your work ethic, that’s your battle level, and that’s unacceptable to me.”

The opening shift set the lopsided game’s tone. A fortunate carom and a uncharacteristically weak back-check by the Tavares line led to Giroux’s goal less than a half-minute after the opening face-off.

From there, it was just a matter of time until the Islanders eclipsed the dubious mark of their worst home loss, set with a 6-0 loss to the Senators on Feb. 20, 2012.

The play symbolized the rest of the afternoon; the Flyers had jump and the Islanders didn’t. By the time the lead grew to a seven-goal differential, the only noise in the arena were “Let’s go Flyers” chants.

At this point, the fans still remaining were either Flyers supporters or beaten-down Islanders fans too despondent to react.

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Islanders defenseman Brian Strait injured his left ankle in the second period and was later placed on the injured list with a fractured ankle. The team activated defenseman Radek Martinek from the injured list to replace Strait. … The second-year coach also said “there’s a good chance” DiPietro will get his third start tonight in Ottawa against the Senators.

zbraziller@nypost.com