Filip Kuba scored 1:16 into overtime to give the Ottawa Senators a 3-2 victory over the Montreal Canadiens on Thursday night.
Bobby Butler got his third point of the game with an assist on Kuba's goal, a drive from the point that got past Montreal backup Alex Auld.
Michael Cammelleri drew Montreal even at 2 with 10.1 seconds left in regulation. Cammalleri beat Craig Anderson from the right side for his 19th as the Canadiens came back to tie it after Butler gave Ottawa a 2-1 lead with his ninth goal 17:11 into the third.
Craig Anderson made 26 saves for the Senators, 13th in the Eastern Conference with 74 points.
Brian Gionta scored his team-leading 27th goal for Montreal, which fell short in its first attempt to give coach Jacques Martin his 600th career win.
The Canadiens clinched their fourth straight trip to the playoffs with a 2-1 overtime win over Chicago on Tuesday.
Auld stopped 29 shots in his first game of the season against his former team.
Butler assisted on Jason Spezza's tying goal early in the third. Spezza tied it a 1 with his fourth goal in three games when he put away a rebound 36 seconds into the third. He drew an assist for his eighth point in three games when Butler snapped a wrist shot past Auld to give Ottawa its first lead with 2:49 left in regulation.
Senators defenseman Francis Lessard got a major penalty and a game misconduct for his hit from behind on Montreal's Tom Pyatt 2:32 into the third.
A short-handed chance by Ottawa's Brian Lee was the best scoring opportunity on the ensuing 5-minute power play. The Canadiens were held without a shot until Anderson stopped Paul Mara's drive from the point with a second left in the major to Lessard.
Canadiens defenseman Jaroslav Spacek returned after missing 23 games because of a knee injury that required surgery.
Gionta scored 13:13 into the second when he put James Wisniewksi's rebound into an open left side before Anderson could lunge across. The Montreal captain put a shot off the left post with 3 minutes left in the second.
NOTES: A moment of silence was observed prior to the game in memory of E.J. McGuire, the NHL's head of central scouting. McGuire died of cancer Thursday at the age of 58. He was an assistant coach for the Senators' first three seasons from 1992-95. ... Anderson is the fifth Senators goalie Montreal has faced this season. ... The crowd of 19,809 was Ottawa's 16th sellout.
(This version CORRECTS Senators 3, Canadiens 2, OT. Corrects Butler's totals in headline.)