Palmieri gave the Islanders a 1-0 lead at 3:32 of the first period. He took a stretch pass from Noah Dobson at the blue line and beat Ullmark five-hole from the right circle.
Palmieri scored his second on the power play to make it 2-0 at 5:27. Horvat's one-timer hit off Parker Wotherspoon and deflected to Palmieri, who swatted the puck into the open net from the left post.
Palmieri then completed the natural hat trick at 12:19 of the first to extend the lead to 3-0. He skated into the rebound of Ryan Pulock's shot and scored from the edge of the crease.
“Palmieri was buzzing out there,” Islanders forward Brock Nelson said. “Good to see him get rewarded. Huge power-play goal. Their line was going all night. They created a lot. So, that was a big difference for us.”
Lee scored 46 seconds into the second period to make it 4-0. He tapped his own rebound into an open net after his initial shot off a rush hit Charlie McAvoy.
Nelson pushed it to 5-0 at 10:24, scoring off his own rebound after receiving a backdoor pass from Horvat.
“It was a big game for us. We want to keep building and are not done,” Pageau said. “I think you saw a team that’s competing and wants to keep climbing, and that's our main focus.”
McLaughlin made it 5-1 at 14:30 of the second period with a one-timer from below the left circle off a pass from McAvoy.
“We just weren’t good enough, weren’t firm enough,” Bruins coach Jim Montgomery said. “We didn’t start the game on time. It’s one of those games where, for whatever reason, we weren’t very good. And now we got to move on to Toronto (on Monday).”
NOTES: Palmieri's hat trick was the first by an Islanders player since Pageau had one on April 3, 2022. ... Bruins forward Pavel Zacha left at 17:19 of the first period with a lower-body injury. ... Islanders forward Mathew Barzal had an assist to extend his point streak to four games (one goal, four assists). ... Islanders forward Matt Martin left the game late in the third period with an undisclosed injury. ... McLaughlin was playing in his first NHL game since Jan. 29, 2023.