The Senators skated off the ice after the first intermission trailing 3-1, but three power-play goals helped Ottawa rally for a 6-4 victory at Verizon Center on Wednesday night.
"I think there certainly were a lot of angry people in there," Senators coach Paul MacLean said of his team's attitude in the dressing room during the first intermission. "At the same time, I thought there was a lot of solution as well within that. As far as being angry, I thought it ended up being more intense and focused on the structure of our game and the work ethic that is needed for our game to work.
"I thought that ended up being the difference in the game. Not anger, but intensity. Not frustration, but intensity."
Zack Smith broke a 4-4 tie when he scored with 2:23 left in regulation, and Bobby Ryan added his second goal of the night into an empty net. In all, five Senators scored and Craig Anderson recovered from a shaky first 20 minutes to make 29 saves.
The Senators got off to a fast start, registering the game's first six shots on goal, but the Capitals gradually titled the ice in their favor, taking the next nine shots and grabbing the lead at 12:10 on Eric Fehr's second goal of the season.
Fehr started the play by pressuring Joe Corvo along the half-wall. Michael Latta picked up the loose puck and was able to push it back to Fehr despite being tripped by a sprawling Bobby Ryan. With room in front, Fehr waited out Chris Phillips and fired a snap shot past Anderson from the slot.
Ryan tied the game at 13:28 when he deflected Patrick Wiercioch's power-play point shot past Braden Holtby (35 saves), but the Capitals regained the lead at 14:06 when Alex Ovechkin's pass from the left circle ricocheted off Marc Methot and Troy Brouwer before finding its way to Marcus Johansson, who was waiting back-door.
Forty-seven seconds later, Brooks Laich beat Jason Spezza to a loose puck in the slot and backhanded it past Anderson. With three goals in 2:43, the Capitals matched their goal total from their previous three games combined.
"We had them," defenseman John Carlson said. "We were close to putting our stamp on it. But we let them back."
The Senators, however, responded with a dominant second period, outshooting the Capitals 19-3 and tying the game with two goals exactly four minutes apart.
Phillips cut Ottawa's deficit to 3-2 at 6:36, ripping a top-shelf slap shot past Holtby on the rush with Fehr in the penalty box for tripping. Colin Greening then tied the game at 10:36 on a nearly identical play, beating Holtby with a wrist shot as he came down the right side.
"It was just a sigh of relief," Greening said. "Also it was the tying goal, so I think all of that together just made it a good moment."
In the third period, the Senators' power play cashed in for the third time and gave them their first lead of the game when Mika Zibanejad's deflection eluded Holtby at 6:05, marking the first time since April 5, 2011, that Ottawa scored three or more power-play goals in one game.
"We're making those mistakes that make us have to take penalties sometimes," Johansson said. "We can't afford that. They had three goals on the power play and that's not OK."
Carlson's power-play slap shot with 3:27 remaining briefly tied the game 4-4; he scored three seconds after drawing a kneeing penalty on Smith. But Smith atoned 64 seconds later when he snapped a stretch pass from Chris Neil past Holtby.
Ryan added an empty-netter to secure Ottawa's first regulation victory in Washington since March 12, 2006.
Meanwhile, the Capitals, whose 38 penalty minutes were their second-most of the season, saw their losing skid reach a season-long four games as they fell to third in the Metropolitan Division.
A frustrated coach Adam Oates was less than pleased with his team's performance.
"We played lousy tonight. Lousy," he said. "We're not going to win games playing this way. We're not. We just proved it."