With Brett Favre playing like his vintage self and the Minnesota defense stepping up, the undefeated Vikings are looking like Super Bowl contenders.

The road to the Super Bowl is about to get much tougher for the Vikings, who open a difficult stretch Sunday when they host a Baltimore Ravens team trying to get back on track after a pair of difficult losses.

One day after turning 40 years old, Favre showed no signs of aging in last Sunday's 38-10 win over St. Louis, throwing for 232 yards and a touchdown.

With 1,069 yards, nine touchdowns and only two interceptions, Favre has helped lead Minnesota (5-0) to its best start since opening the 2003 season with six consecutive wins. It's also the first 5-0 start of Favre's career.

"I hope there's many more to come," he said.

The Vikings have gotten to this point by beating the teams they're supposed to - lowly Cleveland, Detroit and St. Louis - and taking advantage of home matchups with Green Bay and San Francisco. Those first five teams have a combined record of 7-17, but the next three opponents are 8-6.

After this game, Minnesota will visit reigning Super Bowl champion Pittsburgh and rival Green Bay before the bye.

"We're getting a lot of pats on the back," tight end Visanthe Shiancoe said. "But 5-0 can turn into 5-11 and we play a lot of good teams coming up. We can't get content or relax because Baltimore's coming up. It's like hitting a bee's nest, rustling them up a little bit, they're going to be pretty mad coming in here."

The Ravens (3-2) arrive in Minnesota with a chip on their shoulder after letting the last two games get away from them.

Baltimore had a chance to beat New England on Oct. 4, but wide receiver Mark Clayton dropped a fourth-down pass on the Patriots 10-yard line with 28 seconds left in a 27-21 loss.

The defense let the team down last Sunday, as Cincinnati marched 80 yards for a touchdown with 22 seconds left in a 17-14 defeat. The Bengals' final drive was aided by three Baltimore penalties, and the Ravens are tied for second in the NFL with 39 flags on the season.

"We're the same team, basically, at 3-2 or 5-0," Baltimore coach John Harbaugh said. "Essentially we've got the same issues, and the same things we're doing well."

While the Ravens have looked stellar at times this season, very little went right last week.

The offense managed a season-low 257 yards after averaging 31.0 points and 413.5 yards in the first four games, and the once-formidable defense is suddenly showing signs of vulnerability.

Baltimore allowed 403 yards last week and yielded 120 yards rushing to Cincinnati's Cedric Benson, the first time a running back has eclipsed 100 yards against the Ravens in 40 games.

"That's something we take pride in," Baltimore linebacker Jarret Johnson said. "We put it on our backs, that, 'Hey, you're not going to run the ball on us.' And when a team is able to do that, yeah, it's hard. We have to get it fixed."

The Ravens will have to get it corrected fast with Adrian Peterson lining up against them this week.

Peterson was limited to 69 yards on 15 carries against the Rams but scored twice, bringing his season total to a league-leading seven. He is second in the league with 481 yards rushing.

This will be Peterson's first game against the Ravens, as these teams haven't met since Baltimore's 30-23 win on Christmas in 2005.

In Favre's last game against the Ravens on Dec. 19, 2005, the three-time MVP completed 14 of 29 passes for 144 yards and two interceptions in Green Bay's 48-3 loss.

While Favre, Peterson and the rest of the offense is garnering plenty of attention, Minnesota's defense has also been instrumental to the team's success.

With a strong front line featuring Jared Allen, Kevin Williams and Pat Williams, the Vikings are stuffing the run and creating turnovers. Minnesota, the only team that hasn't allowed a rushing touchdown, forced a season-high four turnovers last week and is tied for second in the league with 12 on the season.

While everything has been going the Vikings' way so far, the team is committed to taking this critical stretch one game at a time.

"We're not really looking down the road," linebacker Ben Leber said. "I don't think anybody's looking ahead or looking at the bye week or anything like that. We know it's there. Nobody's concentration is there. We're going to focus on Baltimore and go from there."