The Bruins, coming off a 3-0 victory in Saturday's first game, grabbed a 2-0 series lead with a resounding road triumph.
Marchand set the tone when he scored an unassisted tally just 28 seconds into game, stealing the puck from Sidney Crosby at the blue line, streaking in on goal and beating Tomas Vokoun with a wrist shot.
Brandon Sutter's tally with 34 seconds left in the period seemed to give the Penguins some life, but Marchand struck again only 25 seconds later on a long-range snipe that eluded Marc-Andre Fleury, all but sealing the Bruins' triumph.
Vokoun managed just nine saves on 12 shots while Fleury turned aside 14-of-17 ties for the Pens, who will try to get back into series in Wednesday's Game 3.
Megyn Kelly: Santa Claus and Jesus are both white men
Video of Victoria’s Secret models trying to 'twerk' hits Instagram