Giroux added three assists for Philadelphia, and former Penguins Max Talbot and Jaromir Jagr also scored to help the Flyers take a 2-0 lead in the best-of-seven series.
Ilya Bryzgalov overcame another shaky start to stop 23 shots for the Flyers, who rallied from a pair of early two-goal deficits.
Chris Kunitz had two goals for Pittsburgh, and Sidney Crosby and Tyler Kennedy scored for the second consecutive game.
Game 3 is Sunday in Philadelphia.
RED WINGS 3, PREDATORS 2
In Nashville, Tenn., Ian White and Cory Emmerton scored in the first period, and Detroit evened its series with Nashville Predators.
Johan Franzen also scored, and Jimmy Howard made 24 saves as the Red Wings answered Nashville defenseman Shea Weber being fined only $2,500 for smashing Henrik Zetterberg’s head into the glass at the end of Game 1 on Wednesday.
Game 3 is Sunday in Detroit.
DEVILS 3, PANTHERS 2
In Sunrise, Fla., Martin Brodeur stopped 24 shots for his 100th postseason win, and a three-goal first period was enough to help New Jersey spoil Florida’s long-awaited return to the Stanley Cup playoffs.
Patrik Elias, Dainius Zubrus and Ryan Carter scored in a span of just over 8 minutes in the opening period for the Devils.
Brodeur also picked up an assist for his 10th postseason point, and became the second goalie in NHL history to reach triple-figures in playoff wins.
Only Patrick Roy has more, with 151.
Game 2 is Sunday night, at Florida.