Kris Letang gave the Penguins an early 1-0 lead, but they repeatedly squandered chances to take control by going 0 for 6 on the power play. They are 0 for 20 in four games, three of them losses.
With the teams tied at 1, Daniel Carcillo redirected Matt Carle's soft wrist shot between Marc-Andre Fleury's pads 13:34 into the second period and the Flyers never trailed again.
Giroux sealed it midway through the third with his sixth goal, punching the puck past Fleury after a scramble in front of the Pittsburgh net in which three Flyers players had scoring chances. The power play was created by a penalty for too many men on the ice.
Tyler Kennedy scored off a one-timer of Sidney Crosby's cross-ice pass with 45 seconds remaining, but it was too late for the Penguins as they dropped their third in a row.
The Flyers, outmuscled and outplayed for most of the first period, found their game while killing off Danny Briere's high-sticking penalty early in the second. Mike Richards stole the puck from Letang and fed it to Giroux for a backhander that eluded Fleury. Fleury is 1-5, while Penguins backup Brent Johnson is 4-0-1.
Giroux began this season without a short-handed goal, but has three this season - two in Pittsburgh. The Flyers ruined the Penguins' Consol Energy Center debut Oct. 7 by winning 3-2 on Giroux's short-handed goal, with Bobrovsky making 27 saves in his NHL debut.
The Flyers and Penguins have a history of dislike that dates to their inaugural seasons in 1967, and the first period illustrated that. There were two fights within the first 23 seconds, a shoving match shortly after that and nine penalties in the opening 2:35.
Penguins forward Matt Cooke, accused by Richards of ducking a fight when the Penguins won 5-1 in Philadelphia on Oct. 16, fought Richards 6 seconds after the opening faceoff. The Penguins' Deryk Engelland opened a cut above Flyers forward Jody Shelley's left eye with a right hand punch 17 seconds after that, leaving traces of blood on the ice and Engelland's jersey sleeve. Shelley returned in the period.
Maybe it was too much of the NHL to ask two rivals to play three times in 23 days, and with so many penalties the teams skated 3 on 3 for 1:34. The Flyers wound up with three power plays in the period, yet they lasted only 36 seconds combined.
Once the game finally settled down, Letang carried the puck into the Flyers' zone and passed to Evgeni Malkin, whose giveback pass found Letang open along the right side of the net 8:12 into the first.
Letang has three goals, as many as he scored last season.
NOTES: Philadelphia was 1 for 5 on the power play. ... The Flyers already have made two of their three appearances in Pittsburgh. The teams don't play there again until March 29. ... Pittsburgh is 2-4 in its new arena ... The Penguins are 5-5-1 with three consecutive losses, one in overtime. They started 9-2 last season. ... Philadelphia held out F Nik Zherdev, who was dropped to the fourth line complaining about his ice time.