With the game on the line, Marchand overskated the puck and grazed it slightly on his approach, resulting in a failed shootout attempt and a Flyers win.
Philadelphia's notorious mascot, Gritty, didn't waste any time giving the NHL's master troll a taste of his own medicine.
The Bruins' shootout record dropped to 0-7 this season following the loss, and the team has converted just four of 30 attempts.
The defeat also marked a rare collapse from Boston, which held a 5-2 advantage midway through the game. The Bruins were 199-1-5 dating back to 2010-11 when owning a three-goal lead, according to the Flyers' broadcast.