Scott Hartnell scored twice and Ray Emery made 23 saves for Philadelphia.
Andrew Shaw and Duncan Keith scored and Antti Raanta made 34 saves for Chicago.
Skating down the right wing, Giroux beat Raanta with a wrister to give Philadelphia its third straight win.
Chicago opened an offense-filled first period with two goals just 3:51 into the game.
The first came when Shaw chipped a loose puck near the crease over Emery - the result of a Brayden Schenn turnover at the other end.
Less than 90 seconds later, Keith, set up by a pass from Jonathan Toews, overpowered Emery with a slap shot from the top of the slot.
After the poor start, the Flyers responded with two goals from Hartnell.
Set up behind the net, Hartnell attempted a pass that caromed off Blackhawks center Marcus Kruger and found its way into the net off the left pad of Raanta at 5:48.
Then at 16:27, Giroux walked out from behind the Blackhawks' net and found Hartnell for a one-timer to tie it at 2-2. The goals were Hartnell's 17th and 18th of the season.
Following the first period, the pace slowed in the second, when neither team scored.
Flyers forward Vinny Lecavalier was involved in two chances that nearly broke the tie in the third.
His breakaway attempt with 7:40 remaining was turned away by Raanta's right pad, and Schenn's almost-goal just over a minute later was waved off when referees ruled Lecavalier touched the puck with a high stick on its way to the net.
The Flyers nearly beat Raanta late in regulation, but neither Steve Downie, from a bad angle, nor Schenn, trying to redirect Downie's shot on the far post, could put a Hartnell rebound into a wide-open net.
Notes: The win extends a 10-game, regular-season Blackhawks winless streak in Philadelphia, dating back to Nov. 9, 1996. ... Scratches for the Flyers included defensemen Erik Gustafsson and Hal Gill and forward Jay Rosehill. Scratches for the Blackhawks included defensemen Michal Rozsival and David Rundbland and forward Brandon Saad. ... Despite entering the game with two units ranked in the league's top 10, neither team could take advantage of the man advantage, going a combined 0 for 8 on the power play. ... With the loss, Blackhawks coach Joel Quenneville will have to wait at least one more game to pick up his 700th career win.