"I think we came in here and played a pretty sound game," Biron said. "We just made a couple of mistakes and they capitalized.
"I think this was a real good test for us. We need to prove we're ready for next season."
The Senators opened the scoring at 14:10 of the first when Preissing, who was left alone next to the crease, tapped in a rebound by Comrie.
The Flyers tied the game just over a minute later when Richards came from behind the net and banged in the puck as he caught Gerber falling backwards.
After battling Mike York behind the net, Comrie was able to pull the puck out and beat Biron with a quick shot to give the Senators a 2-1 lead late in the second. The goal was Comrie's first in 13 games.
Comrie was one of three Ottawa players using a special edition pink stick in support of the 2nd Annual Tribute to Hockey Moms to raise money for breast cancer research. Dean McAmmond and Wade Redden also used them.
It had and extra special meaning for Comrie, who was 10 when he lost his mother to breast cancer.
"Losing my mother was not easy," the 26-year-old Comrie said, "and it's not easy to talk about it, but being in the situation I'm in, I want to do everything I can to help."
He scored for the second straight year using the pink stick and joked that he should order a couple dozen with the luck he's had with it.
Schaefer pushed Ottawa's lead to 3-1 at 9:42 of the third, and Hatcher made it a one-goal game with a power play score with 3:24 remaining. It was Hatcher's second goal in two games.
Despite going 0-for-7 on the power play, Ottawa managed to complete sweep of the four-game season series with Philadelphia. Also, Dany Heatley snapped his 16-game scoring streak (11 goals, 13 assists).
"I think this was huge," Gerber said. "Every point is really valuable when you look at the standings. I think we did a much better job than in some of the previous games."