Suisham was forced into action again and he converted from 24 yards, and again just before the half when he fired over from 45 to put his side in command of the game at the break.
In the second half, the Steelers caught a huge break when the Panthers jumped into the neutral zone on a field goal and that allowed the visitors another three attempts to find the endzone.
Roethlisberger managed to evade the rush and throw to Antonio Brown on his way to the ground and the receiver made the catch for the seven-yard touchdown.
The Panthers hit back with another field goal, but Pittsburgh began to pull away from the home side as Roethlisberger and Brown connected for the second time in the quarter for a touchdown strike.
Carolina pulled within 10 points when Newton fired to Greg Olsen down the right sideline and he beat his man to run all the way into the endzone for a 37-yard score.
LeGarrette Blount sealed the win for the visitors when he powered over three tacklers into the endzone with an eight-yard run. Kelvin Benjamin scored a consolation touchdown for the Panthers when he snagged backup quarterback Derek Anderson's pass over William Gay.