Jason Robertson scored two goals, and Jake Oettinger made 24 saves for the Stars (43-21-14), who have won four of their past five games.
Dallas moved two points ahead of the Minnesota Wild for second place in the Central Division after Minnesota lost 4-1 to the Pittsburgh Penguins on Thursday. The Stars are two points back of the Colorado Avalanche, who have one game in hand, for first.
"We obviously want to finish at the top," Stars forward Wyatt Johnston said. "Obviously, Saturday's a big game (against the Vegas Golden Knights), especially when you look at the standings. We want to finish on top, not only of the division, but the conference. It's definitely exciting just battling for position this time of year."
Kevin Hayes scored, and Carter Hart made 26 saves for the Flyers (29-36-13), who have lost five straight (0-4-1).
"Played a good first period, [but we got] real unlucky at the end them going up 1-0," Philadelphia coach John Tortorella said. "Second period, too many men on the ice right away, in our net. Another one of their goals, [Ivan Provorov] wants [Hart] to leave it. He doesn't hear it, he moves it, turnover, in our net. That little surge there where we kind of fueled it, a little bit of self-destruction, that was the game."