Stempniak’s second of the game, five minutes into the third period, squelched the home team’s hopes of a comeback.
Jeff Skinner’s empty-netter completed the scoring.
With less than a minute left in the second period, Stempniak beat Carey Price with a backhand that changed direction off Alexei Emelin.
Playing his first game on LW with new linemates, Alex Galchenyuk opened the scoring 6:46 into the game.
Galchenyuk had an open side to bury a rebound past Eddie Lack for his 16th of the season.
Ten minutes later, Elias Lindholm scored from in close on a dominant Carolina power play.