After 611 days away, Peyton Manning couldn't wait to get back on the field. Ben Roethlisberger seemed determined to keep him on the sideline.

Manning overcame Pittsburgh's 10-minute advantage in time of possession and led a hurry-up offense that helped the Broncos beat the Steelers 31-19 on Sunday night in his Denver debut.

"It's just one game. I try to keep it in perspective," Manning said. "I know how hard I've worked to get to this point. I know how much help that I've gotten along the way, from a lot of people. I'm very grateful for that. It's special. I will definitely say it's special."

The four-time MVP coming off four neck surgeries that wiped out his final season in Indianapolis last year completed 19-of-26 passes for 253 yards and two touchdowns. He was sacked twice and bounced up both times without trouble.

Manning got a big assist from another big-time free agent, cornerback Tracy Porter, whose 43-yard interception return of Roethlisberger's pass with two minutes left and the Broncos clinging to a six-point lead sealed the victory.

"I should've called timeout," Roethlisberger said. "The play clock was running down, I hate to burn timeouts. I should've. We were kind of all over the place.

"There's no one to blame but myself. I already told my teammates and coaches that it's my fault. It's on me. It's disappointing. I hate to let my team down, my coaches, the fans. That loss is squarely on my shoulders. I'll take that and get better and learn from it."

Manning, jettisoned by the Colts in March after missing all of last season with a nerve injury that weakened his throwing arm, took just two snaps in the third quarter. But one was a 71-yard touchdown throw to Demaryius Thomas, Manning's first as a Bronco and the 400th of his career.

He reached the milestone in his 208th career game. Dan Marino did it in his 227th game and Brett Favre in his 228th.