Tyler Seguin scored for Dallas (26-13-5), which had won four of its previous five (4-1-0). Jake Oettinger made 38 saves.
"They were really good, and we were very bad," Stars coach Peter DeBoer said. "It was a combination of both things. ... I thought we were good for about the first minute, we had a couple chances right off the bat, and then the next 59 minutes, they won every race, they won every puck battle. So, just a poor, poor, poor effort."
Walker made it 1-0 at 19:00 of the first period, taking a one-touch backhand pass from Frost and shooting over the blocker of Oettinger on a breakaway.
Philadelphia outshot Dallas 14-1 in the first period and 43-15 in the game.
"I think we were well-prepared in what they do and how good they are, how deep they are," Laughton said. "I just think our sticks in the neutral zone, breaking up plays, creating turnovers and going the other way. It's hard to play against when you play a three-quarter ice game like that and create chances for yourself. Guys have got confidence right now, and it's been fun to watch."