LAKE FOREST, Ill. – After throttling the woeful St. Louis Rams, the Bears defense will face a much more difficult challenge in Sunday night’s first-place clash against the Minnesota Vikings in the Metrodome.

Running back Adrian Peterson, who is beginning to follow Brett Favre and Barry Sanders as notorious Bears killers, has rushed for 423 yards and 7 touchdowns in three career games versus Chicago.

“He’s a monster,” said defensive end Alex Brown. “He runs hard. His offensive line, I don’t think they get enough credit. They play really well and he runs off the blocks from them and then they’ve got play-action [passes] off of it.

“We have to do our job. I believe that the defense starts with the defensive line. If we can have a pretty good day, then we should have a chance to win.”

Brian Urlacher and the Bears defense will face the NFL's second-leading rusher in Adrian Peterson.

A victory would give the Bears (6-5) sole possession of first place in the NFC North as well as the tiebreaker over the Vikings (6-5), who’ve won three of four games since a 48-41 loss to the Bears Oct. 19 at Soldier Field.

“You can say [it’s] the biggest game we’ve had in our division in a long time,” said coach Lovie Smith. “They’re a good football team. They’ve been playing well, especially here of late. We know them, they know us well. It should be a heck of a game.”

Chicago’s defensive line is hoping to replicate its performance against the Rams when it recorded all five Bears sacks and helped hold the St. Louis ground game to just 14 yards on 19 carries.

It was a major improvement over the previous week when the defense was gashed for 200 yards rushing and 227 yards passing in a 37-3 drubbing in Green Bay that was the worst loss in Lovie Smith’s five seasons as coach.

“It came together [in St. Louis] and I’m just hoping that we get put in the same situations where we can attack and be aggressive,” said defensive end Adewale Ogunleye. “Hopefully we can put the same type of game plan we put and the same type of tenacity and energy that we had with the Rams with the Minnesota Vikings.”

The major difference, of course, is that the Bears will face Peterson and Chester Taylor instead of the Rams backfield tandem of Antonio Pittman and Kenneth Darby, whom they held to a combined 18 yards on 16 carries.

“With the Vikings, you have to start with Adrian Peterson,” Ogunleye said. “He’s one of the top if not the top back in the league right now. So we know what we’ve got to do. Their offensive line is very good. [We’ll face] a much better offensive line this weekend than last week. So we’ve got to play stout up front.”

Peterson has enjoyed his greatest success against the Bears at Soldier Field, rushing for 224 yards and 3 TDs last season and 121 yards and 2 TDs this year. In last season’s meeting in Minnesota, he was “held” to 78 yards but ran for two scores in the second half as the Vikings turned a 13-6 halftime deficit into a 20-13 victory.

Peterson hasn’t only excelled against the Bears, however. The seventh overall pick in the 2007 NFL Draft finished second in the league in rushing last season as a rookie with 1,341 yards despite missing two games with a knee injury. This year he ranks second in the NFL with 1,180 yards and 8 touchdowns on 242 carries.

“For us, all 11 guys have got to attack him,” Ogunleye said. “We’ve got to tackle him. Whenever he gets the ball, he’s got to feel us. If he’s going down, we’ve got to try to hit him and not let him get any easy yards because he’s the type of player that if we give him a little bit of a hole, he’ll skeet right through and run by our safeties.

“We’ve seen that. We’ll be watching a lot of that film from last year, this year and everything he’s been doing since he’s been in the league.”

The Bears had four interceptions last Sunday against the Rams. They also picked off four Gus Frerotte passes in their 48-41 win over Minnesota earlier this year but allowed TD drives of 67, 70, 68, 64 and 75 yards.

The Bears defense has performed much better on artificial turf than grass this season. The unit has allowed an average of 265.2 total yards and 49.0 rushing yards in four games on turf compared to 359 total yards and 98.9 rushing yards in seven contests on grass. Admittedly, that stat might be a bit skewed by the fact that two of the opponents the Bears have played on turf, the Rams (2-9) and Lions (0-11), are among the NFL's worst teams.

“I don’t want to knock Soldier Field in the winter, but our field sometimes gets a little rough,” Ogunleye said. “The footing is not as good when the weather gets bad. It does [affect] both sides of the ball, so I guess it balances out. But with the speed of the defense, I think that turf is something that we play better on.

“We’re faster on that. We don’t have these big, bulky guys. We’ve got quick guys like Tommie Harris, and a guy like Tommie is unstoppable on turf.”

Unlike last Sunday when thousands of Chicago fans turned the Edward Jones Dome into a home away from home for their favorite team, the Bears will encounter a hostile environment Sunday night at the Metrodome, where they’ve won just once in their last six appearances.

“Their fans go crazy and it’s a dome and it gets really loud,” Brown said. “It’s a tough place to play. We know that, but we’ve played there before, we’ve won there. 

"We just have to get ready for the week, during the week prepare, get the game plan in and hopefully we can come out with a victory. It’s going to be tough, though.”