The forward has scored 14 goals in the past 17 games after scoring eight in the first 26.
"From the first half of this season, I haven't changed much," Pastrnak said. "To be honest, I think it was a little bit of puck luck earlier, and it didn't go my way. Today is a great example of that, both goals got deflected and went in, so just getting a little lucky."
Taylor Hall had a goal and an assist, Brad Marchand had two assists, and Linus Ullmark made 25 saves for Boston (26-14-3), which is 2-2-1 in its past five games.
"These guys have been around, and they know the importance of [getting points]. We didn't value that tonight, and we weren't very respectful of the game in a number of instances with the puck for whatever reason," Bruins coach Bruce Cassidy said. "At the end of the day, they got [the lead] back, and got a big goal for us on the power play. We held on, got some saves, and got the win."