By Dave Goldberg ~ The Associated Press

Last season, seven NFL teams started 3-0 and only one made the playoffs -- Oakland, which had to suffer through a four-game losing streak before turning back around and getting to the Super Bowl.

So there are no guarantees for anyone yet this season.

Still, most of the unbeaten teams after four weeks seem legitimate, especially Minnesota, which established itself by thrashing San Francisco on Sunday after beating the other three teams in the dismal NFC North.

OK, the 49ers seem to be in trouble, but that's another issue (like why Steve Mariucci was fired).

"We know how good we are," said tackle Chris Hovan, the Vikings' defensive leader. "We just don't talk about it like other teams do. We're not going to go out and yap. We have to prove it on the field."

After Sunday's games, Minnesota and Indianapolis are 4-0. So are Denver and Kansas City, who meet next week at Arrowhead Stadium. Carolina and Seattle are both 3-0.

A look at the unbeatens (in no particular order):

-- MINNESOTA. Sunday's win, the seventh in a row over two seasons, was more impressive than the first three. The defense, the Vikings' weak point even when they were strong, held San Francisco to 125 yards in the first half Sunday when the game was still in doubt. Rookie defensive tackle Kevin Williams, who has combined with Hovan in the middle of the line, had two sacks.

Gus Frerotte was better than a solid replacement for Daunte Culpepper -- 16-of-21 for 267 yards and three TDs. He's not a starter anymore, but he's a perfect backup.

-- INDIANAPOLIS. Forget all the heat Peyton Manning has taken the last couple of seasons for interceptions and multiple checkoffs, six TD passes (without Edgerrin James in the lineup) demonstrates he's still 1-2-3 among NFL QBs. Even more important, the no-name defense (OK, Dwight Freeney is a name) is better in Tony Dungy's second season than in his first.

Still, the Colts have just one win that counts -- Tennessee at home. The victory in New Orleans came against a team that started with a questionable defense, then lost five starters to injury.

-- DENVER. Jake Plummer isn't the next John Elway, but he's been fine since a dreadful opener. The Broncos survived the dreaded "sandwich game" by struggling past Detroit between a win over Oakland and a huge game in Kansas City next Sunday.

-- KANSAS CITY. Dick Vermeil has always won big in his third season with a team, Priest Holmes got healthy and the defense has improved. It's not only free agents Shawn Barber and Vonnie Holliday, it's DT Ryan Sims. In his second season, Sims has become an inside force.

And, of course, there's Dante Hall, who has six returns for touchdowns in his last nine games. After four games (three TD returns), you almost could argue his case for MVP, even on a team that has Trent Green, Priest Holmes and Tony Gonzalez.

-- CAROLINA. Sunday's game was perfect -- Stephen Davis ran for 158 yards and the defense held the Falcons to a field goal. The players also recognize they've done nothing yet -- they were 3-0 last season, lost eight straight and finished 7-9.

"So we're celebrating now, but not for long," said safety Deon Grant, who had a career-high 12 tackles against Atlanta.

-- SEATTLE. Probably better than the Rams and 49ers, who they lead in the NFC West. Ray Rhodes, the new defensive coordinator, has put together a more aggressive defense that won't get back the injured Shawn Springs for a month.

It also helps that Mike Holmgren is a full-time coach now. The Seahawks have six wins, including the last three of last season.

NEXT WEEK'S GAMES TO WATCH:

Denver at Kansas City and Indianapolis at Tampa Bay -- Tony Dungy returns for the first time in a classic duel of offense and defense.