It wasn't long ago that you could question the soundness of Adrian Peterson's knee, Percy Harvin's mood, Leslie Frazier's schemes and Christian Ponder's résumé.

It wasn't long ago that whipping even an outfit as inept as the Titans would have been considered beyond the capabilities of a team that had lost 23 games the previous two seasons.

It wasn't long ago that the NFC North seemed an unfair placement for a young roster and a unproven coach who may have been one more lousy season away from Googling "moving vans."

It wasn't long ago, but five games into a season that was supposed to feature baby wipes and teething rings, the long list of perceived Vikings weaknesses now looks like it was printed on parchment.

Sunday, the Vikings did what good teams are supposed to do: steamrolled an overmatched opponent at home. The surprise is not that the Vikings won; the surprise was contained in the way they so easily embraced and embodied their new standards.

Their 30-7 victory over the stumblebum Titans gave the Vikings more victories in five weeks of the 2012 season than they managed in all of 2011, and the aura of a team that isn't just mumbling platitudes when it talks about titles.

"We've always had the same expectations," tight end Kyle Rudolph said. "Our goal is to win this division. We feel like we've got the talent to do that. That's been our goal since we first met on April 23."

Unprompted, Frazier and several players mentioned that date, the first day they were allowed to work as a team during the offseason. Of course, every team can brag about its spring workouts and promise championships. What's different about the Vikings at this juncture is that they are rapidly improving while their division rivals are growing warts.

The Vikings have lost one game -- at Indianapolis, which just beat the Packers there. The same Titans who spent most of the game being outgained by Percy Harvin beat the Lions, the NFL's version of never-ending Minnesota road construction. The Bears might be the best team in the division, but only when Jay Cutler's mood ring is glowing blue.

Winning three games in a row earns the Vikings nothing, but winning three the way they did, by standing up physically to the 49ers, beating Detroit on the road and manhandling Tennessee, makes what had appeared to be a daunting schedule look much more manageable.

"What stinks is, we should be 5-0," Ponder said. "We had that close game against Indianapolis."

The Vikings look improved not only from last year's disaster; they look improved in the past three weeks.

Their season-opening victory over Jacksonville was shaky, but Ponder's ability to lead them to a comeback victory might prove to be the same kind of seasonal fulcrum as Brett Favre's winning touchdown pass against San Francisco in 2009. Their loss in Indianapolis set off alarms in the locker room.

"We were really disappointed after the first two games because we didn't feel like we played our best ball," said defensive end Brian Robison. "We really felt like we should have been 2-0. We came in, we talked it out, we said some things that needed to be said, we turned it around, and we're playing good ball."

So much has fallen into place. Peterson is the latest product of the Eric Sugarman Limb Regeneration Laboratory and the best running back in the game. Harvin, who briefly pouted this offseason, has become the most unique great player in the league. Frazier stuck with offensive coordinator Bill Musgrave and demoted defensive coordinator Fred Pagac, and both moves worked.

I've heard Frazier promise to deliver a championship in his hometown in Mississippi and in a community center in north Minneapolis; in informal chats by the practice fields in Eden Prairie and during packed news conferences. It all sounds like salesmanship until the team starts to deliver.

"We want to win the NFC North and we want to bring a championship to Minnesota," Frazier said. "Our goals have not changed one bit."

Their credibility, though, has improved quite a bit.

Jim Souhan can be heard Sundays from 10 a.m. to noon and weekdays at 2 p.m. on 500-AM. His Twitter name is SouhanStrib. • jsouhan@startribune.com