Boston
Brandon Carlo and Torey Krug also scored for the Bruins, and backup goalie Anton Khudobin stopped 15 shots. Cassidy took over for fired coach Claude Julien on Feb. 7.
Kyle Palmieri and Devante Smith-Pelly had goals for the Devils, who dropped their sixth straight (0-4-2) as their playoff hopes continue to fade. Cory Schneider made 37 saves.
Spooner one-timed newcomer Drew Stafford’s pass from the right circle for the winner 8:18 into the period.
Stafford, acquired from Winnipeg for a conditional sixth-round pick on Wednesday, nearly had a goal in his Bruins debut midway into the second when he poked a loose puck under Schneider, but it was overturned after a review due to goaltender interference.
The horn went off inadvertently twice early in the third, stopping play both times. Palmieri’s goal tied it seconds after the first stoppage when he converted a 2-on-1 with Taylor Hall.
Carlo’s goal broke a 1-1 tie late second period. The 20-year-old rookie defenseman fired a shot that deflected off the stick of New Jersey wing Nick Lappin, popped into the air and past the stick of Schneider.
Krug had given Boston a 1-0 lead 7:06 into the second when he one-timed a shot inside the left post from the slot for a power-play goal.
The Devils didn’t get their first shot on goal in the second until nearly nine minutes into the period.
Just under two minutes later, after Stafford’s goal was overturned, Smith-Pelly skated in on a clean breakaway and shifted before putting a backhander past Khudobin to tie it.
The game started with two whistles in the initial 14 seconds before the teams went end-to-end for about the next six minutes. Boston had the best scoring chance when rookie Peter Cehlarik fired a wrist shot off the left post.
The Bruins outshot New Jersey 16-5 in the opening period.
Senators 3, Blue Jackets 2
Ottawa, Ontario
Viktor Stalberg got his first goal since joining the Senators ahead of Wednesday’s trade deadline. Erik Karlsson scored his 11th of the season and Craig Anderson made 25 saves.
Stars 2, Panthers 1
Sunrise, Fla.
Klingberg shot from the right circle and the puck went high into the net over the shoulder of James Reimer. The Stars won for the fourth time in six games.
Jamie Benn also scored a goal and had an assist for Dallas. Kari Lehtonen made 40 saves. Tyler Seguin had two assists.
Canadiens 4, Rangers 1
New York
Shea Weber, Artturi Lehkonen, Andrew Shaw and Jordie Benn scored for the Canadiens, who are in first place in the Atlantic Division.
Lightning 2, Sabres 1 (so)
Buffalo, n.y.
Tyler Johnson scored in regulation for the Lightning and Andrei Vasilevskiy made 31 saves as Tampa Bay bounced back on the second night of a back-to-back after losing 5-2 in Pittsburgh on Friday.
Capitals 2, Flyers 1 (ot)
Washington
Backstrom ended the Capitals’ power-play frustrations by beating Steve Mason 3:25 into overtime for his 20th goal of the season. It came with Flyers defenseman Michael Del Zotto in the penalty box for holding, the 12th minor penalty of the game.
Jets 6, Avalanche 1
Winnipeg, Manitoba
Making his 10th straight start in goal, Connor Hellebuyck almost had his second straight shutout for the Jets until Gabriel Landeskog scored with 15.4 seconds left in the game.
He made 22 saves a day after he had a 29-save shutout against the St. Louis Blues.
Patrik Laine scored his NHL rookie-leading 32nd goal, Mark Scheifele had his 27th, Ehlers notched his 21st and Wheeler his 20th.