The Dolphins won the coin toss Sunday and chose to defer.
The Steelers scored immediately. Antonio Brown caught a swing pass on the first drive from Ben Roethlisberger and found room up the sideline, turning it into a 50-yard touchdown.
The Steelers covered 85 yards in five plays to go up 7-0. Roethlisberger was 3-of-3 for 76 yards on the drive.
The Dolphins got one first down before punting on their first possession.
