"To win one by a couple goals, it's been a while since we've done that," said MacTavish.
It was the second victory in a row for the Oilers, who hadn't won in regulation time since Dec. 2. Marty Reasoner and Jarret Stoll also scored for Edmonton, which had six overtime and shootout victories in that span.
"Just to have an easy game, I can't tell you the last time we had one of those," said Horcoff. "They are few and far between. To win the first two games of a five-game homestand, that was big for us and gives us the opportunity to do something special for the last three games. It was a big confidence builder for us."
The Islanders dropped their third straight and remained tied with Philadelphia for eighth place in the Eastern Conference.
"When you lose 4-0, we're battling for a playoff spot, its disappointing," said Islanders defenseman Marc-Andre Bergeron. "But it's just another game, we've got to turn the page and keep going. It's a long season, I know it's a broken record, but that's what it is."
The Oilers outshot New York 12-10 in the first period but Garon and Islanders counterpart Rick DiPietro turned aside everything in the scoreless frame.
Edmonton took a 1-0 lead 1:11 into the second when Hemsky took a low percentage shot that whistled through the legs of defenseman Brendan Witt before beating DiPietro between his pads.
The Oilers extended the lead five minutes later. Dustin Penner banked a pass from the sideboards to Hemsky, who then got the puck to Horcoff. With a backhander, Horcoff scored his 100th NHL goal.
The advantage grew to 3-0 midway through the period as Stoll beat Mike Comrie in a race for the puck and fed Reasoner, who feathered a shot stick-side along the ice past DiPietro.
The Islanders had a chance to get back into the game with 3½ minutes left when Comrie's tipped shot dribbled behind Garon, but the goalie pounced on the puck before it crossed the line.
"I'm feeling really good and very confident right now," said Garon, who turns 30 on Wednesday. "But the way we were playing it always helps a goalie. Defensively we are playing huge. Having a chance to play a lot of games is even better for me and I just want to make sure I make the most of this chance. It felt good to get the shutout."
Edmonton closed the scoring during a third-period power play. Stoll took Horcoff's pass and fired a slap shot past DiPietro.
