Peyton Manning and the Indianapolis Colts stayed unbeaten as week seven of the National Football League got under way.

Meanwhile, Brett Favre and the Minnesota Vikings sank to their first loss of the season.

As the New England Patriots moved to 5-2 and kept the Tampa Bay Buccaneers (0-7) winless with a 35-7 victory at Wembley, the Vikings took a perfect 6-0 record to the Super Bowl champion Pittsburgh Steelers but left Heinz Field on the wrong end of a 27-17 defeat.

The Steelers moved to 5-2 for the campaign after the game turned in their favour in the fourth quarter. With a 13-10 lead, Pittsburgh's LaMarr Woodley recovered a Favre fumble and completed a 77-yard touchdown run.

The Vikings responded with an 88-yard kick-off return touchdown from Percy Harvin but Keyaron Fox sealed victory for the home side as he intercepted a short pass from Favre on the Pittsburgh 18-yard line and ran 82 yards for a touchdown.

In St Louis, Peyton Manning and Indianapolis stayed undefeated after six games after sending the Rams to a seventh defeat this season and 17th loss in succession in a 42-6 rout.

Manning completed 23 of 34 passes for 235 yards and threw three touchdown passes.

The Green Bay Packers geared up for Favre's return to Lambeau Field with the Vikings next week with a 31-3 win on the road at the Cleveland Browns.

Aaron Rogers, Favre's replacement at quarterback in Green Bay two years ago, continues to thrive, throwing three touchdown passes and completing 246 yards to move his team to 4-2 for the season as the Browns slumped to 1-6.

The San Francisco 49ers rallied from 21-0 down at half-time to make a game of it in Houston but three second-half touchdowns from tight end Vernon Davis was not enough to stop the Texans moving to 4-3, a Kris Brown field goal from 50 yards in the fourth quarter consigning the visitors to a third defeat in six games.

Having scored their first win of the season last week, the Kansas City Chiefs reverted to losing ways as Philip Rivers threw three touchdown passes and completed 268 yards in the San Diego Chargers' 37-7 road win.

The Chiefs are now 1-6 while the Chargers are 3-3 after the match-up between the AFC West's strugglers.