Loui Eriksson also scored for Boston, which is 4-0-1 in its past five games, 10-1-3 in its past 14 games. Ryan Spooner added three assists and Brad Marchand added two.
Conor Sheary — Vatrano's college teammate at UMass — got his first two NHL points with a goal and an assist, and Trevor Daley scored his first goal with the Penguins, who are 0-3 since Mike Sullivan replaced Mike Johnston as the team's head coach last weekend.
Overall, Pittsburgh has lost four in a row (0-3-1) and six of its past seven to sit 12th in the Eastern Conference.
Sidney Crosby had two assists for the Penguins to break a three-game point-scoring drought.
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