Pryor managed to compile just 87 passing yards on 10-of-19 efficiency with a pair of interceptions, but the Raiders' defense recorded five sacks and held off a late Steelers charge to help secure the victory.
Darren McFadden carried the ball 24 times for 73 yards and two touchdowns for Oakland (3-4).
Pittsburgh (2-5) picked up 276 total yards on offense as Ben Roethlisberger was picked off twice.
The Steelers signal-caller perked up in the final quarter, but by then it was too late to salvage a win. He finished finished 29-of-45 through the air for 275 yards and a TD pass.
Kicker Shaun Suisham missed two field goal tries from less than 35 yards out down the stretch.