MONTREAL -- Montreal Canadiens head coach and general manager Bob Gainey caught a worrying first glimpse Monday at what his team looks like without injured defencemen Andrei Markov and Mathieu Schneider.
The two defencemen were sorely missed as Dany Heatley scored the tying and winning goals in a span of 38 seconds midway through the third period to lead the Ottawa Senators to a 3-2 win over the Canadiens.
After the game, Gainey refused to confirm how long his top power play pairing will be out of action.
"I can't verify that," Gainey said of pre-game reports that Markov will miss three weeks and Schneider is finished for the season.
Chris Campoli also scored and Alex Auld made 20 saves for the Senators (35-34-10), who won their second straight after losing four of their previous five games.
"It's always a challenge coming into this building, it's a pretty good rivalry," said Sens centre Mike Fisher, who set up Heatley's tying goal. "We haven't let up even though we're out of the picture, and it's always nice beating Montreal, there's no question."
Alex Kovalev and Mathieu Dandenault scored and Jaroslav Halak made 20 saves for the Canadiens (41-28-10), who lost in regulation for the first time in seven games and missed a chance to jump into sixth in the Eastern Conference standings.
The Canadiens remained in seventh place with 92 points, one point behind the Pittsburgh Penguins and three points up on the New York Rangers and Florida Panthers.
Montreal plays the Rangers in New York on Tuesday night in a critical game, and Gainey did confirm that neither Markov nor Schneider would play, though a team spokesman said Schneider would be on the team flight to New York.
The impact of the absence of Markov and Schneider was clear Monday night.
"They're big time players, but when the puck dropped tonight the 20 guys that came to play, our focus was on the game," said Josh Gorges, who logged 25:46 of ice time, his third-highest total of the season. "We can't sit and worry about who's not in the lineup. If I had my choice would I want them in the lineup playing beside us? Of course, but that's out of my control."
The injuries forced Gainey to dress Ryan O'Byrne and Doug Janik, who made his Habs debut after being called up Monday morning from Hamilton of the American Hockey League. O'Byrne was benched for the third period and Janik had only four shifts with 2:09 of ice time in the final frame, while Mike Komisarek played a season-high 26:21 and Roman Hamrlik logged 25:14.
"We started the third with the idea of playing with fewer players, using experienced players and players who had played well to that point of the game," Gainey said. "It's never easy for a player like Janik, playing his first game with his new teammates in a game that was so important to us."
The Canadiens power play was 13-for-35 in the previous six games with Markov and Schneider manning the points.
Hamrlik and Patrice Brisebois took their place Monday but they weren't nearly as effective as the Canadiens power play was shut out on three opportunities after scoring in six straight games.
"We have to give credit to their penalty killing, they were aggressive, they were first on loose pucks and they were in shooting lanes," Brisebois said. "Andrei's not there, Mathieu's not there, so we're going to have to do the job. We know the power play is a huge asset in our game and we're going to have to score one or two goals a night if we want to win games."
With the Canadiens up 2-1 midway through the third Heatley led the Senators to victory.
Fisher corralled a loose puck at the side of the Canadiens net and saw Heatley in front surrounded by three Canadiens, but Heatley still converted the feed for his 36th of the season at 11:23.
"It was only a matter of time before Ottawa scored the way we were playing in the third, we spent a bit too much time in our end," Gainey said. "We played against a good team tonight with a team missing two good players, and that was the result."
On the ensuing shift, Kovalev just missed giving the Canadiens back the lead when he tipped a pass off the inside of the post. As the puck moved back toward the Canadiens end Jesse Winchester took Janik out with a hit in the neutral zone to give Heatley the space to snap his 37th past Halak from the left circle at 12:01 to make it 3-2 Sens.
"I wished that we had the third goal back, a shot under the arm, and I think Halak does too," Gainey said. "But Heatley is a guy who scores 40 goals every year and he gets them in different ways. He got us tonight."
The Senators opened the scoring on the power play at 10:56 of the second when Nick Foligno feathered a nice backhand pass to Campoli on a backdoor rush for the defenceman's 11th of the season.
Kovalev tied it at 12:46 when he took a Saku Koivu pass and wristed his 25th of the year past Auld. Kovalev -- named the NHL's first star for last week -- now has eight goals and eight assists in his last seven games.
Dandenault put Montreal ahead 2-1 with 3.8 seconds left in the second when he tipped Hamrlik's long shot under Auld's glove.
Notes: Wingers Andrei Kostitsyn and Matt D'Agostini were healthy scratches for Montreal, while winger Shean Donovan was scratched for the SensCanadiens D Patrice Brisebois was honoured prior to the contest for playing his 1,000th career NHL game on March 14. NHL senior vice-president Steve Hatze Petros was on hand to present a crystal trophy from the league, while Canadiens Hall-of-Famer Henri Richard presented Brisebois with a silver stick on behalf of the team. The Canadiens will also make a $10,000 donation to Ste-Justine Hospital on Brisebois' behalf Christopher Higgins was awarded a penalty shot at 19:08 of the first period when he was tripped by Auld with an open net, but Higgins couldn't score on the penalty shot. It was the third straight game the Canadiens were awarded a penalty shot, a first in team history. None of the three Canadiens shooters managed to score.