UNIONDALE, N.Y. -- The New York Islanders got all the revenge they could have asked for Tuesday.
The Islanders outskated the Avalanche from puck drop to final horn, more than getting even for a 5-0 loss in Denver 12 days earlier.
"It's two ends of the spectrum," said rookie forward Ryan Strome, whose first goal of the season completed the rout. "We didn't play too bad in Colorado but we didn't get the result we wanted. When you do the right things for 60 minutes, good things happen.
"We have to get down to the basics. Keep doing what we're told to do and hope for the best. We have the [players] in here to do it."
Halak, who made 19 saves in a 1-0 road victory against the Arizona Coyotes on Saturday, has not allowed a goal in his past 143 minutes and 27 seconds, dating to the second period of a 3-2 overtime win at the Anaheim Ducks on Wednesday. The Islanders have not surrendered a goal since 3:49 into the first period of a 2-1 shootout victory at the Los Angeles Kings on Thursday, a span of 181:11.
Halak preserved the shutout by stopping Nathan MacKinnon's breakaway backhander with three minutes left in regulation. He is the first Islanders goaltender with back-to-back shutouts since Rick DiPietro on Dec. 23-26, 2006.
"It's a team effort, same as last game," Halak said. "They blocked a lot of shots, just like they did last game. Everybody was tracking back and we didn't give up many odd-man rushes."
The Islanders have allowed three goals during their four-game streak.
"We were scoring goals but we were giving up a lot of goals," Halak said of the Islanders' first 11 games, during which they relied on their offense to make up for a shaky defense. "We had to get a little better, especially on the [penalty kill]."
The penalty-killers are 12-for-12 in the past three games; against Colorado, they killed all three power plays and scored a shorthanded goal.
Nick Leddy, Anders Lee, Travis Hamonic, Nikolay Kulemin, Casey Cizikas and Strome scored for the Islanders (10-5-0), who've won four in a row and moved within one point of first place in the Metropolitan Division.
The Islanders have been one of the NHL's best road teams for the past two-plus seasons and have a 6-3-0 record away from home in 2014-15. Hamonic knows that for New York to make the Stanley Cup Playoffs this season, they have to find consistency at the Coliseum.
"We have to try to play the same way we do on the road at home," Hamonic said.
The Avalanche (4-8-5) have lost the first two games of a four-game road trip that continues against the New York Rangers on Thursday and are 1-4-1 since beating the Islanders 12 days ago.
"It's as ugly as it gets," center Matt Duchene said. "That was embarrassing."
Semyon Varlamov, who stopped all 40 shots he faced in Colorado's win against the Islanders, again made 40 saves but was beaten six times.
"It's tough to put your finger on what's gone wrong," Duchene said. "It's beyond frustrating at this point. At some point we have to get [angry]. We're like deer in the headlights right now, instead of getting angry and making it happen.
"It's just a game; we've played it our whole lives. It hasn't changed in a thousand years. When you have the puck, you have to make good things happen. You can't just throw a bad pass or throw the problem over to your teammate, because then he's going to have a hard time with it. There's a lot wrong right now."
Colorado nearly scored before the game was one minute old when Duchene broke around Leddy and hit the post with a backhander. But Leddy didn't miss at 1:33 when he took a long rebound of defense partner Johnny Boychuk's shot off the end boards, skated well into the left circle and beat Varlamov low to the short side for his fourth of the season and his 100th NHL point.
The Islanders made it 2-0 at 5:21 on the power play with the help of a fortunate bounce. With Colorado's Jamie McGinn serving a roughing penalty, a right-wing dump-in took an odd hop out of the corner and deflected into the slot. Varlamov tried to play the odd carom with his stick; instead, he gave the puck to Lee, who quickly slammed it into the net for his second of the season.
But the Islanders doubled their lead in the second period, outshooting the Avalanche 15-8 in the process.
The Islanders went up by three at 6:38 on Hamonic's second of the season, then made it 4-0 at 11:32 when Kulemin scored on a shorthanded breakaway. Kulemin has two goals this season; both have come shorthanded.
Cizikas and Strome each scored his first goal of the season in a span of 1:58 in the third period.
"With this being the first game back [from the road trip], I was worried about our energy," Islanders coach Jack Capuano said. "I was impressed with the way they stayed with it."
The Islanders are off to their best start in 13 years. But they know there's still a long way to go.
"It's the most complete game we've played this season," Hamonic said. "But as a group, we can't be satisfied. We haven't done anything yet. We're just  games into the season."