Pastrnak’s two goals included a rare penalty shot—a 27-foot wrister after a penalty to Derrick Pouliot for hooking—that opened the scoring in the second period. Pastrnak scored again on an unassisted 15-foot wrist shot to make the score 2-0.
The Pens closed within 2-1 on a tip-in by Tom Kuhnhacki, assisted by Oskar Sundqvist and Trevor Daley.
In the third period, Boston went ahead 3-1 on a goal by Jimmy Hayes, assisted by Ryan Spooner and Adam McQuaid.
The Bruins stretched their lead to 4-1 on a snapshot by Landon Ferraro, with assists by Dennis Seidenberg.
Boston then closed put the scoring on a 12-foot wrist shot by Brad Marchand, with assists from Torey Krug and Patrice Bergeron, to make the final score 5-1.
Tukka Rask had 41 saves on 42 shots as Boston improved to 33-22-6 for 72 points and third place in the Atlantic Division. Marc Andre-Fleury had 24 saves on 29 shots for the Penguins, who fall to 30-21-8, remaining in fourth place in the Metropolitan Division with 68 points.
The game’s three stars were Pastrnak, Rask, and McQuaid.
The Penguins played without centers Evgeni Malkin and Nick Bonino, who missed their 10th and 17th consecutive games respectively. Pittsburgh was also without defenseman Ben Lovejoy who has missed two straight games with an upper body injury.
The Penguins will return to the Consol Energy Center Saturday afternoon when they play the Winnipeg Jets, while the Bruins will travel to Raleigh to take on the Carolina Hurricanes on Friday evening.