T.J. Oshie had a goal and two assists and 1, on Thursday.
Jason Arnott, Kevin Shattenkirk, Andy McDonald and David Perron all scored for the Blues, who were coming off of Tuesday's 2-1 loss at Columbus. They scored five unanswered goals to win for the sixth time in eight games.
"Some guys are frustrated right now," said Islanders coach Jack Capuano. "We had some opportunities to score some goals. It's not something that I want to continue to talk about with you guys or with our players, because then they're gripping their sticks tighter and they're starting to think about things. We've just got to focus on the process and continue to move forward."
Nielsen appeared to set the tone 59 seconds in, burying a rebound off a Michael Grabner wrister. Instead, the Blues took control, reeling off five straight goals by the end of the second to essentially put the game away.
Arnott tied it with 5:20 left in the first. He settled a short pass from Vladimir Sobotka in front, then sent it high over the left shoulder of Montoya.
Less than three minutes later, Shattenkirk drove home a long slap shot from the left side to send the Blues into the first intermission with the lead.
It was 3-1 just 2:53 into the second courtesy of McDonald's rebound tally, which was set up by Jamie Langenbrunner's slap shot from the right circle.
Perron's redirection near the midway point made it 4-1 and Oshie capped the scoring 14:53 into the second with a tip-in.
"We kind of kept it pretty simple," said Blues defenseman Alex Pietrangelo. "We scored four goals on just shots and tips, doing what we do best. That's putting pucks to the net, getting in front of the goalie's eyes and banging and crashing. I thought every line contributed, a lot of guys answered the call tonight."
The Blues haven't lost back-to-back games in regulation since Ken Hitchcock took over as head coach for Davis Payne in early November...The Blues were 2- for-3 on the power play, while the Islanders were 0-for-5.