Wayne Simmonds and Jaromir Jagr added power-play goals, and defenseman Andrej Meszaros connected at even strength for Philadelphia.
Sergei Bobrovsky made 30 saves.
The Flyers improved to 10-2-1 in their past 13 games, and 13-3-2 on the road this season.
Giroux, the Flyers’ top scorer, had been out since he was injured in a game against Tampa Bay on Dec. 10 when he was accidentally hit in the back of the head by Simmonds’ knee.
Michael Ryder scored in the game’s first minute for the Stars, who were 4-1-0 in their previous five games.
BLACKHAWKS 5, CANADIENS 1
In Chicago, Andrew Brunette and Patrick Sharp scored 21 seconds apart midway through the second period, and Corey Crawford made 20 saves in his first start in more than two weeks as Chicago beat Montreal.
Viktor Stalberg scored midway through the third period and Jonathan Toews and Bryan Bickell added late goals for Chicago.
Stars rookie Richard Bachman stopped 27 shots.
COYOTES 4, HURRICANES 3
In Raleigh, N.C., Lauri Korpikoski scored his ninth goal of the season early in the third period to lead Phoenix over Carolina.
Ray Whitney, a former Hurricanes player, also had a goal and assist for the Coyotes. Cal O’Reilly and Rostislav Klesla also scored for Phoenix.
Tuomo Ruutu got his team-leading 11th goal for Carolina, while Andreas Nodl and Jiri Tlusty also scored.
The Coyotes won for the first time after trailing going into the third period.