UNIONDALE, N.Y. -- The New York Rangers aren't panicking yet, but concern has crept into the club that has been coasting atop the Eastern Conference for most of the season.
They still hold a seven-point lead over the defending Stanley Cup champion Boston Bruins, and are eight points clear of the hard-charging New Jersey Devils -- the Rangers' closest pursuers in the Atlantic Division. But bad habits and careless play have become more the norm recently, producing a slump for the first time in more than two months.
The Rangers trailed 2-0 in the first period and 3-1 in the second before rallying. They couldn't get over the top, losing for the third time in four games (1-2-1) and dropping two straight for the first time since mid-December.
"Very sloppy hockey game. We were a very sloppy hockey club. We're forgetting how we have to do things," coach John Tortorella said of the Rangers, who lost 2-0 at Pittsburgh on Tuesday.
Parenteau scored in the first and second periods after Moulson opened the scoring as the Islanders grabbed a 3-1 lead. But the Rangers bounced back in front of backup goalie Martin Biron and got even on goals by Marc Staal, Marian Gaborik and Derek Stepan.
It wasn't enough as Evgeni Nabokov returned after a bout with the flu. He made 33 traditional saves and three more in the shootout. Frans Nielsen also scored in the tiebreaker for the Islanders, who had lost three of four.
"We were ready to go right off the bat," Parenteau said. "Even blowing a 3-1 lead we showed a lot of character."
Gaborik had the lone shootout goal for the Rangers in four rounds.
Biron made 24 saves through overtime in place of No. 1 goalie Henrik Lundqvist. He had allowed four first-period goals to Chicago in his previous appearance on Feb. 16.
"I haven't been starting games as I would like," Biron said. "We're getting ourselves down and we can't always get out of it. We are in a good place where we are in the conference. We have to bring more desperation to our game right now."
The Islanders threatened to run the Rangers out of the building, stretching their lead to 3-1 and nearly scoring again when Michael Grabner came in on a breakaway midway through the second. Biron turned aside that chance and gave his teammates the opportunity to make a comeback.
Still, the Islanders held tough and beat the Rangers for the second time in five meetings. The Islanders are 13th in the East, six points below the postseason cutoff.
"We did a good job of getting ahead," Moulson said. "We found a way to win."
Gaborik started the Rangers' rally when he took a length-of-the-ice bank pass from Artem Anisimov off the side boards after an Islanders turnover and flipped a shot that eluded Nabokov's glove for his 28th goal, cutting the deficit to 3-2.
Gaborik was involved in Stepan's tying power-play goal, too, 4:51 later. Gaborik slid a pass in the Islanders' end to Stepan for a shot that deflected in on Nabokov. The loose puck in the crease was kicked in by Islanders defenseman Travis Hamonic, who just got back into the lineup after missing nine games because of injuries to his face when he was struck with a puck.
Thinking the goal was scored by Ryan Callahan -- who swung his stick at the fluttering puck in front -- Gaborik fished the puck out of the net. He gave it Callahan, who is one goal shy of 100.
Until then, the night belonged to the high-flying Islanders line of Parenteau, John Tavares and Moulson.
Parenteau did the majority of the damage against his former team, with plenty of help from his linemates. In 11 career games versus the Rangers, Parenteau has seven goals, three this season.
Parenteau gave the Islanders a 2-0 lead. The Rangers got caught in a bad line change that left Michael Del Zotto alone in his end without a defense partner. Tavares made a pass behind his back and between his legs to spring Parenteau, who fired a slap shot from above the right circle past Biron.
Del Zotto was in the penalty box after he illegally swept teammate Brian Boyle's dropped stick back to him, when Parenteau made it 3-1 in the second period. Andrew MacDonald sent a shot from the point into traffic in front. Moulson backhanded the rebound to Parenteau for his 14th goal.
Del Zotto wasn't aware he'd committed a penalty.
"I guess you learn the hard way," he said.
Moulson gave the Islanders a 1-0 lead 6:07 in when Tavares skated one way behind the net and then quickly changed directions before feeding a crisp pass out front to Moulson for his 26th goal. The Islanders scored twice on their first four shots.
Staal brought the Rangers within 2-1 with the first of his team's two power-play goals. The Rangers had been 1 for 15 on the advantage in the previous five games.
LW Ruslan Fedotenko returned to the Rangers lineup after missing six games due to a suspected concussion. ... Biron is 21-4-2 against the Islanders. ... C Casey Cizikas, recalled by the Islanders from Bridgeport of the AHL on Thursday, made his NHL debut. He was in the penalty box when Stepan scored the tying goal. ... Parenteau, who leads the Islanders with 42 assists, already has a career high with 56 points. He has nine points (3 goals, 6 assists) in nine games.