Quarterback Craig Morton directed Denver to a 21-0 first-half lead and the Broncos held Pittsburgh scoreless for three quarters and coasted to a 21-7 win over the Steelers.
The victory left the Broncos tied at 7-1 with the Oakland Raiders for the lead in the AFC West.
The Steelers dropped to 4-4, tying them with Houston and Cincinnati behind Cleveland (5-3) in the AFC Central.
The Steelers played without middle linebacker Jack Lambert and right safety Glen Edwards. Lambert suffered a strained knee ligament last week against Baltimore, and Edwards walked out on Pittsburgh in a contract dispute.
The Broncos sparted into a 21-0 lead with a drive of 65 yards, an 87-yard punt return for a touchdown by Rich Upchurch, and a 20-yard scoring pass from Morton to wide receiver Haven Moses after Pittsburgh fumbled the ball away.
It might have been 24-0 at that juncture if Denver had settled for a field goal instead of trying for a touchdown on a pass from the Pittsburgh two-yard line. Morton was pressured by linebacker Jack Ham and unloaded a desperate, underhanded pass that fell incomplete.
Rookie Rob Lytle from Michigan scored the first touchdown in the opening period, on a one-yard plunge, after Morton passed 24 yards to tight end Riley Odoms to touch off the 65-yard push. Running back otis Armstrong ran 17 yards to put the ball in scoring position.
Upchurch got two blocks at the start of his 87-yard punt return, in high gear with his third or fourth stride and was untouched.
Upchurch returned a punt 42 yards in the second quarter and a spearing penalty against punter Bobby Walden made it a 53-yard gain to the Pittsburgh 11-yard line. But on the fourth down gamble at the two. Morton was harried into his wild throw.
Later in the period, Pittsburgh running back Rocky Blier was stripped of the ball by linebacker Randy Gradisher and safety Bill Thompson recovered for Denver at Broncos' 47-yard line. Morton passed 34 yards to running back Jim Jansen and then 20 yards to wide receiver Moses for the touchdown that made it 21-0.
Terry Bradshaw, still play with a fractured left wrist, took the Steelers 72 years, to the Denver seven-yard line, near the end of the half, mostly on passess a 13-yarder to wide receiver Lynn Swann, 19 to wide receiver Frank Lewis, and 31 to wide receiver John Stallworth.
But Harris was stopped for no gain, Bradshaw almost threw the ball in the stands in his frustration with all his receivers covered and then he was sacked by linebacker Tom Jackson for a 12-yard loss on third down.
The Steelers gambled on fourth and 19, and Bradshaw missed Swann in the end zone. It would not have mattered if the pass had been completed because Pittsburgh was charged with holding on the play.
Denver took possession and ran out the clock with one play.
Besides their fourth-down gamble, the Broncos also tried a third-down quick kick, end a veer formation play, a pitchout from Morton to running back Lonnie Perrin that gained 12 yeards.
Bradshaw missed his first five passes, completing four of 12 in the first half. Morton was four for eight.
There were 14 penalties in the first 30 minutes, seven against each team.
Bradshaw was shaken up near the end of the third quarter when sacked and was replaced by Neil Graff.
End Brison Manor and tackle Paul Smith trapped Bradshaw and he fumbled. Manor continued to lay on the quarterback until the play was over, then signaled to the Pittsburgh bench that Bradshaw was hurt. The quarterback landed on his left side, with his injured wrist tucked in.
The Steelers had just gotten into scoring position when wide receiver Swann ran a fly pattern and was interfered with by safety bernard Jackson, a 50-yard penalty gain to the Denver 28-yard line.
Harris lost four yards on the next play, then Bradshaw fumbled. He stood on the Pittsburgh sideline afterward in no apparent distress.
The Steelers finally scored with 4 minutes 12 seconds remaining on a three-yard pass from Bradshaw to Stallworth.