Heward, who had abdominal surgery in the offseason, scored on a power play 36 seconds into his first exhibition game this year. He later helped set up a goal by Richard Zednik that gave Washington a 2-1 lead.
Brian Sutherby, Kris Beech, and Matt Bradley also scored and Ben Clymer added three assists for the Capitals (2-1-1). Sutherby scored on a short-handed breakaway at 7:08 of the second period when the Capitals were trying to kill off 7:11 of consecutive power-play minutes for the Flyers.
Peter Forsberg scored for the Flyers (1-4) with a 40 foot slap shot at 4:07 of the first period.
Robert Esche allowed five goals on 16 shots before being replaced at 10:26 of the second period by Philadelphia rookie Martin Houle, who stopped six of seven.
There were 27 penalties called, totaling 66 minutes. Washington was whistled for 14 infractions for 34 minutes. The Flyers were 1-for-11 on the power play.