Blair Betts, James Van Riemsdyk and Darroll Powe also scored for the Flyers. Jeff Carter, Kimmo Timonen, and Chris Pronger each added two assists.
Mike Fisher scored for Ottawa. The Senators have lost two straight and four of their last six games.
Emery was with Ottawa for five seasons (three as a regular), but was cut loose after the 2007-08 season, the year after he led the Senators to the Stanley Cup finals. He played in Russia last season.
Ottawa's Pascal Leclaire also stopped 22 shots.
Betts, who signed as a free agent before the season and later missed seven games with a shoulder injury, scored his first goal to put Philadelphia ahead on a power play at 9:34 of the second period. He poked the puck into the net after a dump-in by Claude Giroux took a strange bounce off the boards.
Ottawa tied it on a power play at 14:49 on Mike Fisher's one-timer off a backhand, cross-ice pass from Alex Kovalev.
Van Riemsdyk, who went into the game tied for the NHL rookie points lead, made it 2-1 on another power play at 16:23, scoring from inside the left circle.
Briere increased the lead with a spectacular rebound goal at 6:56 of the third period, batting Carter's shot out of the air. Powe made it 4-1 with a wrist shot at 11:47, and Briere scored on a slap shot 1:52 later.
NOTES: The Flyers' winning streak is their longest since they won five straight in December 2008. Philadelphia has outscored its opponents 23-7 in regulation during the streak. ... Philadelphia has four shots on goal in the first period, a season low for a period. ... Flyers C Briere returned after missing four games (groin and flu).