OTTAWA - The Ottawa Senators suffered a setback as they try to fight their way back into the playoff picture.

The Senators made things that much more difficult on Sunday night, falling 2-1 to the Dallas Stars.

"This is a tough one," said Ottawa defenceman Marc Methot, who played his 500th career game. "Especially with the way we were playing coming off that back-to-back win in Toronto. We were rolling pretty well through the first two periods, even in the third. It's just a shame that we gave up that one goal at the end of the game, but those are the bounces sometimes."

Antoine Roussel scored the winner at 17:46 of the third as the Senators scrambled in their own end.

Jason Spezza also scored for the Stars (40-20-7) with Kari Lehtonen making 23 saves for the win in net.

Despite the win, Dallas coach Lindy Ruff wasn't all that impressed with his team's performance.

"I wasn't happy with our puck movement," said Ruff. "It might be the worst puck moving game for missing passes and not making plays in the three years I've coached here. I said someone has to argue with me, but I can't remember moving the puck that bad inside a game."

Zack Smith scored the lone goal for Ottawa (31-29-7). Andrew Hammond turned aside 23 shots in defeat.

Hammond made his third-straight start as Craig Anderson remains sidelined with a knee injury.

"He's (Hammond) been real good," said Senators coach Dave Cameron. "He's come in, he had a long layoff, wasn't at the top of his game, and he's come in and has found his game. That's what you ask and that's what being an NHL player is about, that you have to find a way."

The loss leaves Ottawa six points back of the Detroit Red Wings for the final wild card spot in the Eastern Conference. With 15 games remaining, the Sens know time is starting to run short.

"We'd be lying if we said we didn't watch the scoreboards," said Smith. "It doesn't change the way we're playing. If anything, it's a little motivation. It definitely makes (Sunday's) loss sting a bit more."

Despite playing the night before, Ottawa was strong in the third period, but struggled to score.

"Right now we're playing good, we're creating chances for each other and we're going to need some puck luck," said Senators captain Erik Karlsson. "We're going to need everybody to score goals. Right now it's been the issue for us — to put the puck in the net."

Ottawa appeared to take the lead five minutes into the third when Curtis Lazar found the back of the net. But the Stars made a challenge that the play was offside and upon review it showed Mike Hoffman was just a step ahead of the play.

Smith opened the scoring with his 18th of the season at 4:45 of the second. Mark Stone made a great pass from behind the net to Smith in front who buried it.

The Stars tied the game at 14:05 on the power play as Spezza fired a shot through traffic. Spezza, a former Senator, has now scored a goal against all 30 NHL teams.

"It's one of those things you don't think about, but just kind of like to have," said Spezza. "Beating your old team, it definitely feels good."

Despite a scoreless first period the Senators were able to gain some momentum off some good scoring chances.

Smith was stopped from in close and Ryan Dzingel had a great chance midway through the period, but Lehtonen was solid.

Ottawa heads out for a two-game road trip with stops in Carolina and Florida before returning home to host Toronto on Saturday.

Notes: Ottawa defenceman Michael Kostka made his Senators debut in place of Patrick Wiercioch. ... The Stars were without left winger Patrick Sharp (lower body) and right winger Patrick Eaves (ill).