Week seven of the NFL left one unbeaten team standing and few - if any - would have picked them out at the start of the season.

The Kansas City Chiefs were beaten at defending champions the Seattle Seahawks while the San Francisco 49ers also suffered their first loss.

But the Minnesota Vikings marched on to maintain their 100% record, and there were also big wins for the Cleveland Browns and Denver Broncos.

Here are the biggest stories from Sunday's games in the NFL.

Kansas City and Seattle have not only won three of the past four Super Bowls, they came into week seven with this season's best offence and best defence respectively, in terms of total yards.

Sunday's primetime match also marked the return of Kenneth Walker, the Most Valuable Player in last season's Super Bowl, to former team Seattle after joining the Chiefs in the off-season.

The running back has made a stunning start with Kansas City, leading the NFL in rushing yards per game (133) after six weeks, but Seattle's defence was determined to show why they became known as 'the Dark Side' during last season's championship run.

They stifled Patrick Mahomes and the Chiefs, restricting Walker to 36 yards from 14 carries as KC tied for their fewest points in a game with Mahomes as their starting quarterback.

Seattle quarterback Sam Darnold also continued to lean on Jaxon Smith-Njigba, with last season's offensive player of the year claiming 150 receiving yards and a touchdown, while new running back Emanuel Wilson finished with 100 rushing yards and a score.

The Seahawks ran out 20-3 winners to improve their record to 4-3, while the Chiefs are now 5-1.

Brock Purdy went to the top of the all-time list for career passer rating last week but did not hit his normal high standards as the San Francisco quarterback was frustrated by the Atlanta Falcons.

The hosts forced four turnovers, including two Purdy interceptions, as they won 29-20 to inflict a first loss on the new Super Bowl favourites.

The 49ers are 6-1 while NFC West rivals the Los Angeles Rams - the pre-season favourites - got back to winning ways.

The Rams are 3-4 after winning 35-21 at the Las Vegas Raiders, where Matt Stafford became the first player to lead two teams for touchdown passes.

Last season's MVP previously set the franchise record for the Detroit Lions before joining the Rams in 2021.

They next face the Los Angeles Chargers, who are the last remaining winless team after the Miami Dolphins won 28-25 at the New York Jets.

For the first time in the NFL, two divisions will go into week eight with all four teams having a record better than 50%.

One of those is the NFC North, topped by the Minnesota Vikings. Before the season, half the NFL was considered to have a better chance of winning the Super Bowl.

But they are the last undefeated team at 6-0 after coming from behind to win 16-10 at home to the Indianapolis Colts.

Their defence has been one of the league's best, Will Reichard is yet to miss a kick and - although their offence is yet to catch fire - the Vikings keep grinding out victories.

Including the end of last season, Kevin O'Connell's team are on an 11-game win streak, but they face a test at divisional rivals Detroit next week.

After naming new signing Kyler Murray as their starting quarterback, the Vikings traded JJ McCarthy four weeks ago and he impressed on his first start for the New York Giants on Sunday, leading them to a 27-21 win in overtime at the Houston Texans.

Elsewhere in the NFC North, Jessie Bates kicked a field goal as time expired to hand the Detroit Lions a 20-17 win over the Green Bay Packers.

Only three field-goal attempts have been missed from inside 35 yards all season and Green Bay rookie Trey Smack missed two of them on Sunday.

All AFC North teams also have at least four wins, with the Pittsburgh Steelers kicking off Sunday's action by beating the New Orleans Saints 16-10 in the NFL's first game in France.

The Cleveland Browns (5-2) then regained top spot after Andre Szmyt made his third game-winning kick in four weeks to claim a 27-24 win at the Tennessee Titans.

Deshaun Watson was booed by Cleveland fans in pre-season but has now led five game-winning drives this season and is beginning to look like the player he was at Houston, which convinced the Browns to sign him on a fully-guaranteed deal in 2022 worth $230m (£172m).

Their other divisional rivals went head-to-head. The Baltimore Ravens had to manage without quarterback Lamar Jackson for a third straight game and led the Cincinnati Bengals 13-0 at half-time.

But the Bengals stormed back to win 35-13, with Joe Burrow throwing for four touchdowns and 292 yards as the Ravens suffered a second straight loss.

Baltimore have not set a return date for two-time MVP Jackson (ankle) and have a tough trip to the Buffalo Bills next week.