Anton Khudobin stopped 25 shots for Boston, which blew leads in each of its previous two games and lost both.
David Krejci also scored for Boston, and Brad Marchand had a pair of assists. With the win, the Bruins moved three points ahead of Toronto in the Northeast Division while remaining one point behind first-place Montreal.
For six months, it's a really good accomplishment. But as soon as April [11, the end of the regular season] comes around, no one thinks about the regular season anymore. For six months, it's a real battle to get into the playoffs in the NHL these days. There are a lot of good teams, and it takes consistency over a long time.
— Ducks coach Bruce Boudreau on clinching a playoff berth after a win against the Islanders on Saturday