The Detroit Lions suffered their first defeat of the National Football League season on Sunday, their 25-19 loss to the San Francisco 49ers leaving the Green Bay Packers as the only unbeaten team after six weeks of play. Another early season pace-setter, the Buffalo Bills, also came crashing down to earth with a 27-24 loss to the New York Giants while the Indianapolis Colts, still without injured quarterback Peyton Manning, slumped to 0-6 following a 27-17 defeat at Cincinnati. The 49ers improved to a 5-1 record after an impressive comeback victory at Detroit. Alex Smith found Delainie Walker with a six-yard touchdown pass in the fourth quarter to put San Francisco ahead with 1:51 left on the clock. The Lions were unable to find a first down on the next possession against some outstanding defense from the 49ers before a 37-yard David Akers field goal made sure of a 25-19 win for San Francisco. The win was a big statement from the 49ers – as well as becoming the first team to beat the Lions, it was their third straight win on the road. To rub salt into the wound for Detroit, their first loss meant they gave up top spot in the NFC North – to defending Super Bowl champions, the Green Bay Packers. The Packers easily dealt with the winless St. Louis Rams, quarterback Aaron Rodgers throwing three touchdowns in the 24-3 victory at Lambeau Field. Rodgers threw for 310 yards and the highlight of yet another masterclass from their quarterback was a career-long 93-yard touchdown pass to Jordy Nelson. The Bills (4-2) have been the surprise package of the season so far but their limitations were on show at the New Meadowlands where the Giants' Ahmad Bradshaw ran for three touchdowns and 104 yards for New York. The scores were tied at 24-24 when Bills quarterback Ryan Fitzpatrick was intercepted, for the second time, by Corey Webster. Giants quarterback Eli Manning then led a drive down the field which ended with Lawrence Tynes's 23-yard game-winning field goal. Tom Brady led the New England Patriots to a 20-16 comeback victory over the Dallas Cowboys – the win means that Brady and head coach Bill Belichick have won 116 regular season games, equalling the NFL record held by former Miami Dolphins head coach Don Shula and quarterback Dan Marino. The Patriots were three points down with just 22 seconds remaining on the clock when Brady found Aaron Hernandez with an eight-yard touchdown pass. The Oakland Raiders (4-2) beat the Cleveland Browns (2-3) 24-17 but will likely be without quarterback Jason Campbell for some time. The Philadelphia Eagles earned a much-needed win with a 20-13 victory at Washington. In other games, Baltimore beat Houston 29-14, Atlanta defeated Carolina 31-17, Chicago beat Minnesota 39-10 and Tampa Bay downed New Orleans 26-20.