Trent Hunter tipped in Miroslav Satan's shot to snap a tie with 5:01 left and the Islanders - behind another solid effort by DiPietro - beat the struggling Boston Bruins 3-1 Saturday night.
The Islanders, 5-1 since the Olympic break, won all four games with the Bruins this season. Boston, which climbed into the Eastern Conference playoff chase in February, is 1-5 since the break.
New York won for the second straight night, despite unloading four veteran players - two forwards and two defensemen - at the trading deadline, but coach Brad Shaw had a simple reason for the success.
"You can win any game with goaltending like that," Shaw said. "The last two games, and from the Olympics on he's played outstanding hockey."
DiPietro made 32 saves for the Islanders, including three good ones in the closing 2:27.
"I think we just played with a lot of desperation. I think we realize these are our playoffs every night," DiPietro said. "We're trying to get back in the thick of the playoff race and I think we played hard and smart tonight and played with the desperation we needed."
The Islanders, in a 10th place-tie with Toronto, remained seven points behind eighth-place Montreal, and moved four points ahead of Boston.
"We're not giving up in here," Hunter said. "We've raised our level of intensity and we have to be desperate every shift and we've been able to do that."
Satan circled from the right wing to the point and sent a seemingly harmless wrist shot toward the net. Hunter, positioned in front, got a stick on it, sending it past goaltender Tim Thomas. Alexei Yashin added an empty-net goal with 23.3 seconds left.
Thomas stopped 42 shots.
"We've got to score goals," Boston coach Mike Sullivan said. "It's tough to win games when you only score one goal. Obviously, that's been our nemesis the last couple of games."
The Bruins were shutout 3-0 by the Canadiens on Thursday and lost a pair of 3-2 games before that.
"We had a couple of chances, but that's probably the story here. We've had chances, but the guys can't score," said Boston right wing Mariusz Czerkawski, who played his first game after being claimed off waivers from Toronto on Wednesday.
DiPietro made a sliding stop on Marty Reasoner, who was alone in front, with 2:27 to play. He also had a pair of nice saves against Brad Stuart in the closing 1:10.
After a scoreless opening period in which each team had a decent number of good scoring chances, Boston took a 1-0 lead on Brian Leetch's power-play goal 13:46 into the second. Leetch slipped a wrist shot between DiPietro's pads from the slot after collecting Brad Boyes' pass.
The Islanders tied it on Mike York's goal 2:04 later. York redirected Hunter's pass at the edge of the crease after defenseman Joel Bouchard picked up an errant clearing pass at the blue line and slipped a pass to Hunter.
The game became somewhat chippy midway into the second period after Boston's Hal Gill and New York's Eric Godard fought. The teams even had a scrum along the boards when the second-period horn sounded. Boston's David Tanabe was called for roughing, the only penalty that came from the skirmish.
Notes: The Bruins had a pair of crushing hits on Islanders in the opening period. Patrice Bergeron leveled Bouchard, and Travis Green sent D Radek Martinek to the ice in front of the benches. ... Boston D Nick Boynton served his NHL-imposed one-game suspension for "an inappropriate threatening gesture" against Montreal's Mike Ribeiro in Thursday's 3-0 loss. ... Czerkawski was whistled for hooking in his first shift. Czerkawski, and centers Reasoner and Yan Stastny each played their first game with the Bruins. Reasoner and Stastny were acquired from Edmonton for Sergei Samsonov on Thursday.