DALLAS -- If the Dallas Stars are to make a late run at the playoffs, their offense will need to keep clicking at the current rate.
"We have confidence offensively," said Richards, who reached 20 goals for the seventh time in his career and has three goals and four assists in his last four games. "Sometimes it doesn't happen, but for most of the year at home, we've been pretty good offensively.
"Sometimes we forget the little things you do to get good offense, and I think that's what we forgot early after the break. But we've got enough talent here to score goals."
Richards made it 3-all at 16:37 of the second when he beat sprawling Senators goaltender Pascal Leclaire from low in the left circle.
Benn converted James Neal's setup with 52.9 seconds remaining in the second to put Dallas in front, and Daley made it 5-3 on a wrist shot from the right circle at 4:33 of the final period.
At that point, coach Cory Clouston replaced Leclaire with Brian Elliott after Leclair had allowed five goals on 19 shots.
"You can't give up five goals on the first 18 or 19 shots," Clouston said. "You're going to give up chances. But it's very tough to get the momentum back."
Kari Lehtonen stopped 25 shots in his third straight start for Dallas, which improved to 75 points with 11 games remaining.
Dallas is 3-6-1 since the Olympic break.
"We know what's at stake," Daley said. "We know it's an uphill battle. It's desperation time. [Teams ahead of Dallas in the Western Conference playoff race] aren't going to let us get by them. We can only control what happens in this room."
Spezza's third goal pulled the Senators within 5-4 with 1:27 left.
The Senators couldn't capitalize on a 6-on-4 advantage in the final 40 seconds when they had a power play and pulled their goaltender.
Mike Fisher and Spezza scored on the Senators' first two power plays after Ottawa had gone 0 for 14 with the man advantage during the previous four games.
But the Senators, who've been outscored 22-9 during the five-game skid, lost the lead twice and fell to 1-7-1 since the break.
Ottawa, which has 10 games left, had won a franchise-best 11 in a row and 14 of 16 before the Olympics. But the Senators have been unable to recapture that success and remain stuck on 79 points.
The Senators were without scoring threat Milan Michalek, who injured his left leg in Thursday night's game in Atlanta. Michalek tried to practice on Friday but left the ice early in the session. Michalek and Fisher share the team lead with 22 goals.
Fisher's deflection on the Senators' first power play gave Ottawa a 1-0 lead 1:06 after the opening faceoff.
Richards tied it on the power play with a one-timer from the right point at 13:55 of the first period.
Ribeiro converted Krys Barch's centering pass at 17:31 of the opening period to give Dallas a 2-1 lead, but Spezza's power-play goal with 1.7 seconds left in the first period pulled Ottawa even.
"That put a damper on things," Daley said of Spezza's tally at the end of the opening period. "We talked about it [between periods]. I think we did a good job of responding."
Spezza's deflection at 5:11 of the second period gave the Senators a 3-2 edge, but Ottawa allowed the lead to slip away.
"Right now I'm pretty frustrated," Spezza said. "This time of year it's all about wins. I'd be happier with nothing [no goals] and winning the game and moving up in the standings instead of losing a game like we did tonight."
Ottawa matched its season-long losing streak. ... The Stars played the fifth game of a six-game homestand. ... Dallas C Mike Modano sat out his third straight game while recovering from an appendectomy. ... Ottawa was making its first trip to Dallas since Dec. 7, 2007, and second since the 2003-04 season. ... Leclaire hasn't won since Jan. 3.