The Flyers are looking at a two games to one deficit after defenseman Wade Redden scored 6:43 into overtime Tuesday to give the Senators a 3-2 victory. Philadelphia never has won in 11 all-time series when falling behind three games to one.
Philadelphia blew a pair of leads in Tuesday's contest, and has been held to less than three goals in four of its last five games.
"It's frustrating," said Flyers left wing John LeClair, who scored his second goal of the playoffs 4:35 into Tuesday's game. "To play against that team, you have to play with the lead. We've gone out and done that, but we have to do a better job of not sitting on it. We need to keep playing hockey and being more aggressive with the lead."
Ottawa had been 0-22 all time in the playoffs when trailing after two periods, but capitalized on a power play as Marian Hossa scored his fifth goal of the playoffs 22 seconds into the third. The Senators also converted their only other man advantage in Game Four, when Daniel Alfredsson beat Roman Cechmanek from the left faceoff circle 66 seconds into the second period to make it 1-1.
The Senators were 1-for-11 on the power play in the first two games, but they have held the Flyers without a goal in nine chances with the man advantage.
"That's something we missed in Game Two that we could have capitalized on," Alfredsson said of the Senators' power play, which was second overall during the regular season. "Tuesday (night), it was the difference."
Game Five is Saturday at Ottawa.