Marchand (two goals, one assist), David Pastrnak (one goal, two assists) and David Krejci combined for nine points for the Bruins (17-10-4), who have won three in a row and haven't lost to the Coyotes since Oct. 9, 2010. It's the longest active regular-season winning streak against one opponent in the NHL.
Tuukka Rask made 30 saves for Boston, which scored its four goals in a 4:50 stretch of the second period after falling behind 1-0.
WATCH: [All Coyotes vs. Bruins highlights]
"I think we talked about for the most part; it wasn't anything crazy, it was about respecting what was going on," Bruins coach Bruce Cassidy said. "I thought we were a little disrespectful to the game. It showed in our power play; we were trying to force plays, not being hard enough, supporting one another. Then we talked about making some adjustments and closing our gaps and allowing our D to stay up for our forwards to work back, and we got some good transition opportunities and goals off of that."
Nick Schmaltz, Nick Cousins and Michael Bunting scored, and Darcy Kuemper made 22 saves for the Coyotes (13-14-2), who have lost three in a row. The Coyotes had won their previous three road games.
"We played a good hockey game for 50 [minutes]," Coyotes coach Rick Tocchet said. "We had a really good game ... it's 2-0 and we backed off again. It's very frustrating. We cannot back off. That's something that we've got to keep pressing here. It's a learning process."
Schmaltz scored on a one-timer from the left face-off dot to give the Coyotes a 1-0 lead at 12:22 of the first period. The initial shot hit the post, but it deflected off Rask's skate and into the net.
Cousins extended the lead 40 seconds later with a wrist shot from the top of the right circle that went off John Moore and past Rask on the short side to make it 2-0.
Heinen scored at 8:40 of the second period to make it 2-1. After Ryan Donato dumped the puck into the Arizona zone, Jakob Forsbacka Karlsson won a battle and made a backhand pass to the front. Heinen kicked the puck to his stick with his right skate and scored on a slap shot.