After taking a pass from Daniel Alfredsson, Kuba beat Carey Price with a slap shot from the top of the left faceoff circle. Erik Karlsson assisted on Kuba's winner, giving him four points in his last three games and 71 points in 71 games on the season.
Kuba scored on Ottawa's 33rd shot as the Senators passed idle Boston for first place in the Northeast, although the Bruins have two games in hand.
Colin Greening also scored for the Senators, while Tomas Plekanec had a goal for the Canadiens.
JETS 3, CAPITALS 2
WINNIPEG (AP) — Dustin Byfuglien crashed the net and scored the go-ahead goal in the third period as the Winnipeg Jets defeated the Washington Capitals.
As Byfuglien skated in front of Capitals goalie Tomas Vokoun, Evander Kane sent the puck into the crease and the big defenceman tipped it in at 9:21 of the third. Winnipeg moved into ninth place in the Eastern Conference with 76 points, one point ahead of idle Buffalo.
The Jets are also just two points behind the eighth-place Capitals.
Andrew Ladd and Nik Antropov also scored for Winnipeg. Brooks Laich and Mathieu Perreault had goals for Washington.
BLACKHAWKS 4, STARS 1
DALLAS (AP) — Dave Bolland and Patrick Sharp scored in the game's first two minutes, Corey Crawford made 21 saves, and the surging Chicago Blackhawks beat the Dallas Stars.
Bolland's 18th goal of the season came 10 seconds in, and Sharp made it 2-0 at 1:42 with his 27th.
Sharp and Marian Hossa added goals in the opening two minutes of the third period to put the game out of reach for Chicago, which improved to 6-1-1 in its last eight games.
Jamie Benn ended Crawford's bid for his sixth career shutout with 5:50 remaining for his 22nd goal of the season.
OILERS 3, FLAMES 1
EDMONTON (AP) — Ryan Nugent-Hopkins scored a pair of goals and the Edmonton Oilers ended the Calgary Flames' five-game winning streak.
Jordan Eberle had a goal and two assists for the Oilers, who won their second in a row.
Mark Giordano had the lone goal for the Flames, who remained in a tie for ninth place in the Western Conference with San Jose, a point behind eighth-place Colorado.
The game got off to a scary start as Oilers star Taylor Hall lost his balance and took a hard shot to the head from Flames defenceman Cory Sarich along the boards. Hall looked woozy as he was helped off the ice to the dressing room and did not return to the game.
KINGS 4, DUCKS 2
ANAHEIM, Calif. (AP) — Alec Martinez, Anze Kopitar and Justin Williams scored first-period goals, and the Los Angeles Kings kept pace in the Western Conference playoff picture with a victory over the fading Anaheim Ducks.
The Kings won the Freeway Faceoff series 5-1. Last season, the Ducks swept a season-ending home-and-home set with their Southern California rivals to clinch a playoff berth — marking the only time both teams made it to the post-season in the same year. This is the fifth time during the Ducks' 18-year rivalry with the Kings that they ended their season series with 10 or more games left on the schedule.
Cam Fowler and defenceman Luca Sbisa scored for the Ducks, who outshot the Kings 42-19. Jonas Hiller made 19 of his 39 saves in the second period after giving up three goals on eight shots in the first.