Pittsburgh quarterback Mason Rudolph looked far from a back-up as he connected with some of his side's stars, including a 34-yard dime hauled in by wide receiver JuJu Smith-Schuster for a score which gave the home side the lead in the third quarter.
Miami's defence regularly put pressure on the rookie 24-year-old QB through the first 30 minutes while his counterpart – veteran signal-caller Ryan Fitzpatrick – threw a pair of touchdowns to Albert Wilson and Allen Hurns as the Dolphins raced into a 14-0 lead.
But Pittsburgh hit back with 27 unanswered points as their defence dominated when necessary.
The Steelers held onto the ball for 35 minutes and then their secondary forced four Miami turnovers.
Pittsburgh improved to 3-5 for the season and the Dolphins are now 0-7.