The decisive boot capped a 12-play, 75-yard Steelers drive that came after the Eagles had grabbed a 14-13 lead on Brent Celek's two-yard touchdown grab.
Rashard Mendenhall, returning this week from an injury, keyed the final push with 31 rushing yards, finishing the game with 101 total yards from scrimmage and a score.
Ben Roethlisberger connected on 21-of-37 passes for 207 yards for Pittsburgh.
LeSean McCoy picked up 80 yards from scrimmage and caught a touchdown pass for the Eagles (3-2).
Michael Vick connected on 20-of-30 passes for 175 yards and a pair TD passes in the loss.