Stutzle gave Ottawa a 4-3 lead at 14:17. Drake Batherson waited for a lane in the slot to open up and then fed a cross-ice pass to Stutzle, who lifted a wrist shot over Bruins goaltender Joonas Korpisalo’s outstretched glove.
Dylan Cozens and Claude Giroux each had a goal and an assist, Shane Pinto scored and Leevi Merilainen made 18 saves for the Senators (9-5-4), who extended their point streak to seven games (4-0-3).
David Pastrnak and Morgan Geekie each had a goal and an assist, and Korpisalo made 17 saves for the Bruins (11-8-0).
Giroux gave the Senators a 1-0 lead at 1:28 of the first period, one-timing a cross-ice pass from Stutzle on a power play.
Cozens one-timed a centering pass from Fabian Zetterlund over Korpisalo’s blocker from the high slot to push it to 2-0 at 19:03.
Geekie cut it to 2-1 at 11:49 of the second period. He tapped in a pass from Pastrnak behind Merilainen, who was caught sliding too far over to cover the shooting threat.
Pinto redirected a centering pass from Michael Amadio under Korpisalo’s right arm on a 2-on-1 rush to make it 3-1 at 1:06 of the third period. Earlier in the day, Pinto signed a four-year, $30 million contract extension with Ottawa.
The Bruins thought they’d scored at 2:45 when Pastrnak scored with a long range wrister on a power play, but Ottawa challenged for offside and the call on the ice was overturned. However, 1:04 later, Pastrnak made it count for real when he scored on a loose puck at the edge of the crease on the same power play to cut it to 3-2 at 3:49.
Matt Kastelic tied it 3-3 for the Bruins at 5:15, chipping the puck over Merilainen in tight off a Tanner Jeannot rebound.
Stutzle scored into an empty net for the 5-3 final at 19:42.
