The Pittsburgh Steelers didn't get off to a strong start this season, but the defending Super Bowl champions are now playing at a high level.

Pittsburgh goes for its fifth straight victory Monday night, when it looks to snap a three-game losing streak to a Denver Broncos club trying to bounce back from its first defeat of the season.

Since opening the season 1-2, the Steelers (5-2) have gone undefeated to give themselves a legitimate shot to win a third straight AFC North title. They own the same record as Cincinnati, although the Bengals currently own the tiebreaker by virtue of a home win over Pittsburgh in Week 3.

"We've put ourselves in a good position to go into this bye, but November, December, that's where the real teams start to separate themselves," Steelers defensive end Brett Keisel said. "Hopefully, if we're a real team around here, we can continue this win streak."

Pittsburgh will attempt to continue its surge in Denver, where it hasn't won a regular-season game since a 34-17 victory on Oct. 14, 1990.

The Steelers, though, defeated the host Broncos by the same score in the 2005 AFC title game en route to their Super Bowl 40 victory.

Coming off its bye week, Pittsburgh looks to build off a 27-17 home win over Minnesota on Oct. 25.

Ben Roethlisberger, third in the NFL with 2,062 passing yards, threw his 11th touchdown of the season, while the Steelers' defense scored twice in the fourth quarter -- a 77-yard fumble return by linebacker LaMarr Woodley and Keyaron Fox's 82-yard interception return with one minute remaining.

Pittsburgh had four sacks -- with James Harrison recording two to increase his team-leading total to eight -- while holding the Vikings' Adrian Peterson-led running game to 89 yards.

The Steelers, who haven't allowed a 100-yard rusher in their last 25 regular-season contests, lead the league in run defense at 76.6 yards per game.

Pittsburgh, though, will have a patchwork defensive line when it faces rookie running back Knowshon Moreno, Correll Buckhalter and the Broncos' 11th-ranked rushing offense.

Defensive end Travis Kirschke, who was replacing the injured Aaron Smith (torn right rotator cuff), suffered a torn left calf muscle in the victory over Minnesota.

Nick Eason -- Keisel's backup at right defensive end -- will move to the left side, while rookies Ziggy Hood and Sunny Harris are expected to get plenty of playing time as the Steelers rotate linemen in Denver's Mile High altitude.

"I was released (by Pittsburgh) the fourth game and the next thing you know I'm playing," Eason said Wednesday. "Now I'll be playing a lot more. My snaps have doubled in three weeks. It's amazing, but that's the life story in the NFL."

The Steelers' makeshift line will not have to contend with Broncos third-year right tackle Ryan Harris, who suffered a toe injury in last Sunday's 30-7 loss at Baltimore. Tyler Polumbus will likely make his first NFL start in Harris' place.

"We always give (Tyler) plenty of reps in practice. He handled himself well in the preseason," Broncos first-year coach Josh McDaniels said. "We'll expect him to go in there and play well."

McDaniels' team did not play well last week, dropping its first game of the season following a 6-0 start.

"Anytime you have a game like this, it forces you to look in a mirror," he said. "Hopefully we can find out just as much about one another ... through the adversity of a loss as you can through six wins."

The Broncos' defense is looking to rebound from its worst effort of the season. Denver ranks third in the NFL in rushing defense at 86.1 yards per game, but surrendered a season-high 125 to the Ravens.

"Last week was last week," Broncos safety Brian Dawkins said. "We did some things in the second half that were not like us defensively. Getting out of our gaps -- I think we were trying to do too much towards the end -- and we gave up some scores that we usually don't give up."

Denver will try to slow a Steelers running game led by Rashard Mendenhall -- who has a team-high 418 yards and four scores -- and veteran Willie Parker.

Parker, who rushed for 93 yards on 21 carries in the teams' last meeting -- a 31-28 Steelers loss at Denver on Oct. 21, 2007 -- missed practice time this week due to a fever, but is expected to play.

"Pittsburgh is going to pound the ball," Broncos defensive lineman Kenny Peterson said. "They have a physical offensive line. Their mentality has been the same for decades, which is physical play."

Denver's offense looks for a better effort after posting a season-low 200 yards last week, when they went scoreless in the first half for the first time this season.

"Yeah, they beat us up pretty good, no question about it," quarterback Kyle Orton said. "We feel like we've got a physical football team and certainly Pittsburgh prides themselves on that, too. So, it'll be a hard-hitting game and whoever can win that battle is going to have a good chance to win."

Denver, which leads the all-time series 13-6-1, has won nine of 12 overall versus Pittsburgh.