DENVER -- The Denver Broncos are your 2012 AFC West champions.

With a 31-23 victory against the Tampa Bay Buccaneers at Sports Authority Field at Mile High, Denver ensured at least one home game in the postseason for the second consecutive season.

"It's a great accomplishment, a tribute to the staff and coaches in that locker room," Head Coach John Fox said. "They did a fantastic job. But we still have a whole quarter of the season left. We'll see what happens."

Midway through the third quarter on Sunday, it didn't look like the Broncos were on their way to a celebration.

Denver struck first on its opening drive of the game, moving the ball 65 yards down the field on 10 plays, capping the effort with a 1-yard pass from Manning to defensive tackle Mitch Unrein for a 7-0 lead.

But the Bucs scored 10 unanswered points courtesy of a 31-yard Connor Barth field goal and an 11-yard touchdown catch by tight end Dallas Clark to take the lead.

Meanwhile, the Broncos ended four consecutive drives with punts as the offense stalled and the Bucs held their lead into the second half.

"We had some self-inflicted penalties, some mistakes we thought were hurting us," said quarterback Peyton Manning, who finished with 242 passing yards, three touchdowns and an interception. "Believe me, (Tampa Bay) has an excellent defense, but we thought we were doing some things to make it a little tougher."

To Manning's point, the Broncos committed six penalties in the first half, which cost them 60 yards. Then, everything turned.

Thanks to a 21-yard punt return by Trindon Holliday -- who gained nearly 100 yards on four punt returns -- the Broncos started their second drive of the second half near midfield.

Four plays later, Manning found wide receiver Demaryius Thomas in the end zone on an 8-yard strike. The touchdown pass was Manning's 28th of the season, setting a new Broncos record. Most importantly, it gave Denver a lead it never relinquished.

After the defense forced a Buccaneers three-and-out, the offense got back to work. Manning found Thomas in double coverage for the pair's second touchdown connection to cap a seven-play drive and extend Denver's lead.

On both scores, Manning placed the ball where only Thomas could come away with it.

"It's great," said Thomas, who led the team with 99 receiving yards. "You get better and better, and you see him getting better and better. You want to get better for him, because you know he's going to give you a chance where it's tough for defenders to get to the ball."

On the second play of Tampa Bay's ensuing drive, Unrein hit Buccaneers quarterback Josh Freeman as he let a pass fly, and linebacker Von Miller was there for his first career interception. The reigning AFC Defensive Player of the Month took the pick 26 yards for the club's fifth defensive touchdown of the year.

In five minutes and 25 seconds of game time, the Broncos turned a 10-7 deficit into a 28-10 lead.

"Right plays at the right time," cornerback Champ Bailey said of how the run came together. "Von's play was big just to give us that swing. Our offense got clicking later in the game, and that's really what it's all about. We kind of complemented each other and both made plays on both sides of the ball."

But the game wasn't quite out of reach just yet for the Buccaneers.

On the first play of the fourth quarter, Barth capped off a drive that began due to a Manning interception by knocking home a 50-yard field goal to pull Tampa Bay back to within two scores. While the Denver offense answered with a field goal of its own on the ensuing drive, Prater missed a 47-yarder later in the quarter to keep the Bucs' hopes alive.

Barth made a 55-yarder with a little more than three minutes in the game to make it a 15-point game again -- 31-16.

Tampa Bay kicked the ball deep and used two of its timeouts to get the ball back with 2:57 in the game, and proceeded to capitalize with a 5-yard touchdown pass from Freeman to wide receiver Mike Williams to pull within eight.

Wide receiver Eric Decker held onto the ensuing onside kick, however, and a first-down run by Knowshon Moreno allowed Manning to take a knee to seal a Broncos win.

"It says a lot about the character guys on this team," Moreno said of the team's big third-quarter effort. "At the same time, that's why you've got to play four quarters, because they still had a chance there at the end. But we came together and did what we had to do to make sure we came out with the victory."

The defense pointed to Tampa Bay's late comeback effort as an area to improve, and offensive players noted a need to build a rhythm earlier in the game.

That attitude of striving for perfection, even after a playoff-clinching win, stuck with Miller.

"I feel like we've only scratched the surface of the team that we know we can be," he said. "We just have to keep on going to be that team that we all know that we're capable of being."