DENVER -- For quarterback Peyton Manning, Sunday's season-opener at Sports Authority Field at Mile High carried plenty of significance.

After missing the entire 2011 season with a neck injury, Manning was released by his former team, joined the Broncos and continued months of rehab to be able to run through the tunnel in Week 1.

Fittingly, his memorable performance was capped off with a win -- and a bit of history.

On Sunday, Manning became just the third quarterback in NFL history to throw for 400 touchdowns in his career. He did so in 18 fewer games and 473 fewer pass attempts than Dan Marino and Brett Favre, respectively.

"Dan Marino and Brett Favre are two of my favorite players of all time — two of the best quarterbacks of all time," Manning said after the game. "I don't really feel comfortable being in that company, but to be mentioned amongst them is truly humbling and quite an honor. It's not one I take lightly."

"There are a lot of people that participated in that process — a lot of receivers on different teams throughout the years — and I'm grateful for their help," he continued. "I guess you would call it an individual record, but I accept it on behalf of many great teammates and coaches."

Manning's 400th career touchdown -- his first as a Bronco -- came with his team trailing midway through the third quarter, needing a spark.

He provided it, with some help from wide receiver Demaryius Thomas.

At halftime, the offense recognized a certain formation that saw Pittsburgh send a blitz off the back side of the formation. So running back Willis McGahee faked a run to the strong side, and Manning threw a quick screen back to Thomas right where the blitzers were coming from.

"You can just tell the adjustments that he can make," cornerback Champ Bailey said. "You throw something at him, he'll come back in the second half and make you pay. He showed it tonight. That's the Peyton I know."

The result was a 71-yard, catch-and-run touchdown that gave the Broncos a 14-13 lead and capped off a quick, two-play drive.

"We weren't thinking an 80-yard touchdown — maybe a 9-yard gain is kind of what I was thinking — so it sure was a nice surprise," Manning said. "Some really good blocking on that play; (guard) Zane (Beadles) had a good block and (tackle Ryan) Clady … (wide receiver) Matt Willis came all the way from the back side to get the safety, and, of course, Demaryius did the majority of the work and really turned it on with great speed. Just a huge play."

Tight end Jacob Tamme had a key block at the beginning of the play, as well, and then had one of the best seats in the house to soak in the big play.

"I had a block and then I got to watch it go all the way down the field," he said. "I had a great view. That type of stuff, man, that's why you play. It's awesome for him to get 400. At that time, even more awesome for us to go up. That was a lot of fun."

Thomas said it was a special moment in his career to catch Manning's 400th touchdown pass, but he wasn't thinking about it while he was running down the field. He thought about it plenty after the game, however.

"I was like, 'You're going to let me keep the ball, right?'" Thomas said. "He said he'd think about it, but he got one of the game balls, so he gave me that ball."

"Hopefully he'll sign it for me," he laughed.

In all seriousness, Thomas said he was excited to be play a crucial role in such a historic moment.

"I can always go back and tell my grandkids, 'I'm in the record books,'" he said.

Steelers quarterback Ben Roethlisberger called it "an awesome accomplishment," and Pittsburgh safety Troy Polamalu wasn't surprised by what he saw.

"What can you say? I mean, he's Peyton Manning," Polamalu said.

Reaching the milestone was just part of Manning's Broncos debut, in which he completed 73.1 percent of his passes for 253 yards and two touchdowns.

But it was an appropriate way to start the next chapter of his career.

"It definitely is a special win," Manning said. "I know how hard I've worked and how many people have helped me in this process. I'm grateful, and I'm definitely appreciative of the moment and the opportunity."