Boston, which entered the night 3-for-18 on the power play, was 3-for-4 with the man-advantage. Anaheim was 0-for-5.
"Mikey was our best killer," Sturm said of DiPietro. "Penalty kill did outstanding. Power play was the difference."
Matthew Poitras pushed the lead to 4-2 at 16:20, finishing a 2-on-1 rush with Hagens past the right pad of Dostal.
Washe gave the Ducks a 1-0 lead with 38 seconds remaining in the first period. He slid a wrist shot along the ice from above the left circle that went through the legs of linemate Jeff Malott and continued through the pads of a screened DiPietro.
The Ducks scored again just 21 seconds later to make it 2-0. Sennecke intercepted a clearing pass in the neutral zone, skated into the middle of the ice, and passed off to Cutter Gauthier, who made a touch pass to Nesterenko driving through the right circle. Nesterenko then quickly fed Sennecke, who was cutting toward the far post and redirected the puck into the net.
"They came out pretty hard. They had a lot of juice the first half of the game," Sturm said. "But also knowing, as a young team, it's tough to keep that tempo up for 60 minutes, and I was just hoping that they were going to slow down, and I think that's what happened."
NOTES: Lindholm went 18-for-23 on face-offs, and the Bruins as a team went 40-for-58 (69 percent). ... Pastrnak scored his 423rd goal with Boston, moving him past Brad Marchand for sole possession of fourth in team history. ... Anaheim had killed 11 straight penalties coming into the game. ... Ducks forward Mikael Granlund did not play because of an upper-body injury. He's day to day. ... Gauthier returned for the Ducks after he missed the 4-2 loss to the Flames on Tuesday with an upper-body injury. He played center for the first time in his NHL career, going 4-for-20 in the face-off circle.