Carter Camper, David Krejci, Brad Marchand also scored as the Bruins wrapped up a six-game road trip.
Tim Thomas collected 27 saves for the Bruins, who increased their lead over Ottawa to five points atop the Northeast Division.
The Senators, meanwhile, saw their four-game losing streak snapped despite a pair of late goals from Daniel Alfredsson.
2014: NFL Cheerleaders [PHOTOS]
Arizona Cardinals player formally charged