The Flyers had limited Byfuglien to just one assist in the first four games of the series but he sparked an offensive onslaught Sunday that featured a goal and two assists each by Kris Versteeg and Patrick Kane, and a goal and assist apiece from Brent Seabrook, Dave Bolland and Patrick Sharp. Eleven different Blackhawks had at least one goal or assist.
Antti Niemi got the win, despite allowing four goals on 27 shots.
Michael Leighton stopped three of the 13 shots he faced in goal for Philadelphia. Brian Boucher allowed three goals on 14 shots to take the loss.
The Flyers got goals from Scott Hartnell, Kimmo Timonen, James Van Riemsdyk and Simon Gagne.
Game 6 is scheduled for Wednesday in Philadelphia.