The Stars were whistled for two penalties in an 11-second span during overtime, first for too many men on the ice and then on a crosscheck by Esa Lindell against Marchand, and Boston eventually made the play to win.
Marchand took a pass from David Krejci after an assist from Torey Klug and beat Dallas goaltender Anton Khudobin low on the glove side for the game-winner. The victory was the first in three overtime games for the Bruins this year.
The loss snapped a three-game winning streak for the Stars, who are 3-1-1 so far on their six-game road trip.
Flyers 5, Coyotes 2
Claude Giroux scored two goals and Sean Couturier had a goal and an assist as Philadelphia finished a four-game road trip without a regulation loss after a victory over Arizona in Glendale, Ariz.
Shayne Gostisbehere had a goal and an assist and Oskar Lindblom scored into an empty net late as the Flyers went 3-0-1 on a Western trip that began with victories in Anaheim and Los Angeles and included an overtime loss to San Jose on Saturday.
Alex Galchenyuk and Michael Grabner scored for the Coyotes, who had a five-game winning streak broken.
Capitals 4, Oilers 2
Washington, which still is looking for consecutive victories this season, snapped a two-game losing streak.
Goalie Pheonix Copley earned his second win of the season and the second of his NHL career. The rookie finished with 31 saves, including 11 as he blanked Edmonton in the third period.
Devils 5, Penguins 1
Brian Boyle had a natural hat trick as New Jersey broke a three-game losing streak by defeating host Pittsburgh, which lost its fourth straight.
Boyle, who recently announced he was in remission after being treated for leukemia, got his first career hat trick on Pittsburgh's Hockey Fights Cancer night. He scored the final goal of the first period and the only two of the second.
Will Butcher had a goal and two assists, Travis Zajac scored, and Jean-Sebastien Dea had two assists for the Devils. Keith Kincaid stopped 35 of 36 Pittsburgh shots. Jamie Oleksiak scored for the Penguins.
Canadiens 4, Islanders 3 (SO)
Joel Armia scored in the fifth round of a shootout as Montreal rallied to beat host New York, which saw its five-game winning streak end.
Armia scored the lone goal of the shootout when he ripped a wrist shot over Thomas Greiss to complete Montreal's comeback from a 3-1 deficit.
Canadiens backup goaltender Antti Niemi capped a 21-save performance by making five shootout saves. Jonathan Drouin, Max Domi and Artturi Lehkonen scored in regulation for Montreal, which rallied from a 3-1 deficit. Casey Cizikas had two goals for the Islanders, who also got a goal from Valtteri Filppula.
--Field Level Media