Martin Havlat scored twice to help Ottawa end Philadelphia's 12-game unbeaten streak with a 4-1 victory Monday night.
Ottawa has eliminated Philadelphia, a point ahead of Vancouver in the overall standings, from the playoffs the last two seasons.
"I think there are some psychological issues that need to get dealt with," Flyers coach Ken Hitchcock said. "Whether we've got to draw them out or whatever, I think those are real and they've got to get dealt with.
"If we want to be a championship team, we cannot pretend that the psychological issues are going to be hidden. ... They are preventing people from performing at their best."
Philadelphia, 10-0-2 in November, has lost just three times in regulation and hadn't been defeated since a 3-2 loss in New Jersey on Oct. 30.
Havlat opened the scoring early in the second period, the first time the Senators have scored the first goal in a game since Nov. 3. He made it 2-0 late in the period with a power-play goal.
"We haven't been starting very well," Senators center Shaun Van Allen. "We're always behind the 8-ball, and you have to put so much energy just to come back and tie. It's so much easier for the team that scores first."
Flyers captain Keith Primeau scored a short-handed goal early in the third, beating goalie Martin Prusek on a two-on-one rush with defenseman Eric Weinrich while Ottawa was on a two-man advantage.
Senators defenseman Anton Volchenkov restored Ottawa's two-goal lead midway through the period, scoring his first goal of the season off a centering pass from Marian Hossa.
The Senators were denied a goal with 4:18 remaining when a video review determined that Hossa's pass in front on a power play was kicked in by Radek Bonk at the edge of the crease.
Daniel Alfredsson scored into an empty net with 1:16 left.
Ottawa improved to 3-4-0-2 in its last nine games.
"I think it's always a close game against them," Alfredsson said. "It's two really good teams that have been playing really well defensively the last few years. This year, they're the much better team than us so far, but we play them really tight every time we play them."
Prusek made 31 saves, starting in place of Patrick Lalime, who fell ill with the flu prior to the game.
"It was a big effort from everyone," Alfredsson said. "We know Philadelphia pretty good, and they know us pretty good. I thought our goaltender was better tonight and we scored our goals at the right time."
Neither of Havlat's goals came on direct shots on goal.
On the first, Havlat's attempted pass to Bonk struck Weinrich's right skate and was redirected past goalie Robert Esche into an open left side.
Havlat made it 2-0 just four seconds after Ottawa failed to score on a four-on-three power play. With the puck behind the goal line, Havlat fired the puck into the crease at Esche, banking the puck into the net off the goalie's right pad.
"I never saw the puck," Esche said. "Once I heard it hit the boards, it was already coming out. (Havlat) made a good play and banked it off me. It was a fluky goal. Obviously, I'm not happy with any goal I give up, but that happens."
|Martin Havlat (3) ASST: Radek Bonk (14), Vaclav Varada (4)|
1 - 0 OTT
|PPG - Martin Havlat (4) ASST: Wade Redden (6), Daniel Alfredsson (15)|
2 - 0 OTT
|SHG - Keith Primeau (3) ASST: Eric Weinrich (3)|
2 - 1 OTT
|Anton Volchenkov (1) ASST: Marian Hossa (15)|
3 - 1 OTT
|EN - Daniel Alfredsson (10) ASST: Peter Schaefer (6), Todd White (4)|
4 - 1 OTT
|Wade Redden Holding against Mark Recchi|
|Zdeno Chara Cross checking against Tony Amonte|
|Wade Redden Roughing against Keith Primeau|
|Keith Primeau Roughing against Wade Redden|
|Mark Recchi Tripping against Todd White|
|Jeremy Roenick Roughing against Chris Neil|
|Vaclav Varada Roughing against Jeremy Roenick|
|Eric Desjardins Cross checking against Marian Hossa|
|Justin Williams Slashing against Vaclav Varada|
|Robert Esche Roughing against Radek Bonk|
|Mark Recchi Tripping against Daniel Alfredsson|