Philadelphia's Simon Gagne, right, reacts to his third-period go-ahead goal on a sprawling Alex Auld. (Tom Mihalek/Associated Press)

What a way to start an eight-game road trip.

Simon Gagne's fluky go-ahead goal late in the third period quashed an inspired rally by visiting Ottawa and propelled the Philadelphia Flyers to a 6-4 win on Tuesday night.

After the Senators erased a 4-2 deficit with tallies by Dany Heatley and Chris Phillips, Gagne's bouncing shot went in off the skate of Ottawa defenceman Jason Smith with 5:30 remaining.

Healtey also scored in the second period, and Nick Foligno had a first-period goal for Ottawa (12-15-5), which remained tied with Los Angeles for the fewest away wins in the NHL (three).

Alex Auld allowed five goals on 31 shots for the Senators, and has given up 19 goals in his last four starts.

"We're a fragile team, but I thought we came out and showed some desperation in the third period," Ottawa coach Craig Hartsburg said. "We have to show more desperation. We're in a desperate state here. We have to get points. We had a chance to get a point tonight and let it slip away."

Jeff Carter scored his NHL-leading 26th goal for Philadelphia (19-8-7), which has earned a point in eight of its last nine games.

"When you're winning games on a regular basis like we are, it makes everything easier," Carter said. "Everybody's got confidence in this room. If we give up a couple of goals late or get down a goal late, nobody panics on our bench. We keep going right to the end."

Matt Carle, Joffrey Lupul, Andreas Nodal and Mike Richards — into an empty net — also found the webbing for the Flyers, while Antero Niittymaki made 17 saves.

The Senators, who have lost five times in regulation in their last seven games, are being forced out of their home rink by the men's world junior hockey championship, which begins on Boxing Day in the nation's capital. The NHLers don't return to Scotiabank Place until Jan. 10.

Ottawa will be back in action after the Christmas break with a game in Calgary on Saturday night (CBC, CBCSports.ca, 10 p.m. ET).

Sens roar back

The Senators took the early lead with Foligno's fifth goal of the season at 5:01, but it was short-lived. Carle tied it 92 seconds later, and Lupul gave the Flyers the lead heading into the intermission when Scott Hartnell's bad-angle shot hit his leg and went in.

Heatley evened things up with a power-play goal three minutes into the second. Stationed at the right post, he tapped in Jason Spezza's cross-crease pass.

The Flyers — decked out in their sublime orange throwback jerseys — retook the advantage three minutes later as Carter enjoyed the fruit of his own labour. Hauled down by Christoph Schubert on a shorthanded charge, Carter was back on the ice for the ensuing power play and showed once again why he shouldn't have been left off the NHL's all-star ballot.

Nodl's marker stretched Philly's advantage to two going into the final period, but Ottawa wouldn't go away. Heatley drew the Sens within one by pouncing on a bouncing puck in the slot at 7:40, and Phillips tied it three minutes later when his blast from the point found its way past a screened Niittymaki.

"It was one of those games that it was kind of hard to find the puck, and there were a lot of bad bounces," the Flyers goalie said.