Radek Bonk had a power-play goal and an assist and Marian Hossa set up a pair of power-play tallies for the Senators, who grabbed a three games to two lead in the conference semifinal series and can end it Monday in Philadelphia.
"Tonight, everybody brought their best to the table," Hossa said. "It was a really important game for us. They scored first, but we found a way to bounce back by getting some power-play goals. Our special teams were key again."
Cechmanek cannot handle prosperity, falling to 1-8 lifetime following a playoff win. He was coming off his second shutout of the series but stopped just 12 of 16 shots and was replaced by Robert Esche.
"I don't know how you can fault him," Flyers Coach Ken Hitchcock said. "We had a seeing-eye dog goal win us a game, 1-0. Their first two goals (were similar). The first one went off a stick and the second went off Lappy's (Claude Lapointe) pants. (Roman) will be good (in Game 6). He was great and not-so-great, so he'll be great."
The Flyers scored first for the fifth time in as many games on Claude Lapointe's goal 21 seconds into the game. But it was all Ottawa thereafter.
Martin Havlat and Bonk struck in a 1:49 span of the second before Peter Schaefer's shorthanded goal made it 5-1 just under seven minutes into the third.
"The point is, we all know we have to be better," Philadelphia center Jeremy Roenick said. "Roman knows he has to be better, I know I have to be better, every player down the line knows it. There's no question."
Lapointe stunned the Corel Centre crowd when he sneaked behind defensemen Curtis Leschyshyn and Anton Volchenkov, got a pass from Donald Brashear and wristed a shot that trickled through goaltender Patrick Lalime.
"We still had a lot of time left because they scored in the first shift," Hossa said. "Bryan's goal gave us a great lift. We knew then we could get back if we just played our game."
Smolinski came off the bench on a sloppy line change and wristed a shot from a stride inside the blue line that may have hit a stick before finding room under the crossbar. It was his first playoff goal since Game 6 of last year's Western Conference quarterfinals.
Philadelphia's Mark Recchi put a shot off the right goalpost with just under eight minutes to go in the period and teammate Dmitry Yushkevich took a tripping penalty at 15:14.
The Senators needed just 10 seconds on the ensuing power play to take the lead for good as Alfredsson fired a slap shot from the blue line that found its way through four players in front of the net and eluded Cechmanek.
"The first goal was a shot off my shoulder and the second was a shot I didn't see because the guy stayed in front of me," Cechmanek said. "It doesn't matter what was the score, 1-0 or 5-2, it's just one game and when we come back Monday, we'll see."
Cechmanek made a pokecheck to break up a shorthanded scoring chance by Hossa with just under 13 minutes to go in the second period but did not last much longer.
Havlat made it 3-1 at 8:07 when he got a rebound at a bad angle on the right side and flicked it in for his third playoff goal.
Roenick took a high-sticking penalty at 9:29 and Bonk scored Ottawa's second power-play goal just 27 seconds later. Cechmanek stopped a shot by Havlat and had the rebound put through his pads by Hossa. Defenseman Wade Redden retrieved the puck and threw it in front, where Bonk put it past the out-of-position goalie.
"Even down 3-1, we were really right in it," Hitchcock said. "They seemed to be giving up as many chances as they were getting. I thought the difference in the hockey game were once they got those two fluky goals, we had a lot of chances on the power play, couldn't finish as Lalime made some great saves."
With 3:24 to go in the period, Michal Handzus came out of the penalty box and had a chance from the slot but was stopped by Lalime. Moments later, Handzus was clobbered behind the net by Leschyshyn and went to the locker room.
After Flyers defenseman Kim Johnsson put another shot off the goalpost, Schaefer and rookie Radovan Somik traded goals in a 56-second span of the third period.
The final 3 1/2 minutes featured a series of skirmishes, with Chris Neil of the Senators and Philadelphia defenseman Jim Vandermeer drawing major penalties for fighting.
"It was nasty. We're just letting them know we're not going away," Flyers captain Keith Primeau said. "They beat us tonight to take a lead in the series, but we're gonna go home and put up 100 percent. You could say we've put ourselves in a position we're most comfortable."