Patrice Bergeron took a pass from Brad Marchand and tipped it in over Ilya Bryzgalov's glove side as he waited right in front of the net just 50 seconds into the game.
That lead didn't last long though, and Flyers forward Maxime Talbot scored 1:15 later after the puck went off Dennis Seidenberg's skate and past Bruins goaltender Tim Thomas.
The Bruins scored twice more in the first period with goals from Tyler Seguin and Milan Lucic.
Seguin's goal came on the power play (and there were plenty of penalties in the period--36 minutes worth in fact.) The Bruins had a span where they had a couple of 5-on-3 man advantages with both teams getting heated in the period, and Seguin took advantage of it, wristing one past Bryzgalov 9:01 into the first.
Lucic continued the scoring and earned two of the three requirements needed for the Gordie Howe hat trick--the goal and the fight. His fight came just 1:24 into the period, when he dropped gloves with Flyers forward Tom Sestito.
In the first period alone, the game has already seen two fights, the 36 penalty minutes and four goals.
Tim Thomas has made nine saves off ten shots, and Bryzgalov has 12 saves of 15 shots.