The Detroit Lions erased a 24-point deficit to stun the Dallas Cowboys 34-30 Sunday and join the Green Bay Packers as the only undefeated teams in the National Football League (NFL).

For the second straight week, the Lions clawed back from the brink of defeat to improve to 4-0, their best start to a season in over three decades.

It wasn't pretty, but it was beautiful, Detroit head coach Jim Schwartz said after Calvin Johnson scored the winning touchdown with 1:39 to go.

Detroit's comeback win took them level at the top of the NFC North division standings with last season's Super Bowl champion Packers, who saw off the Denver Broncos 49-23 with ruthless efficiency.

Packers quarterback Aaron Rodgers, the most valuable player of last season's Super Bowl, tossed four touchdown passes and ran in two more while Charles Woodson recorded his 11th career interception return for a touchdown.

The Buffalo Bills, who jumped out to a surprising 3-0 start to the 2011 season, suffered their first loss when they dropped a nailbiter to the Cincinnati Bengals 23-20.

The Bills enjoyed big comebacks in their past two games but gave up a seven-point, fourth-quarter lead against the Bengals, who sealed the win when Mike Nugent kicked a 43-year field goal as time expired.

Eli Manning threw two touchdowns in the final four minutes as the New York Giants overcame a 10-point deficit to beat the Arizona Cardinals 31-27 while Tom Brady threw two touchdown passes to steer the New England Patriots to a 31-19 victory against the Oakland Raiders.

Brady now has 274 touchdown passes in his career, the ninth most by any quarterback and one ahead of his boyhood hero Joe Montana, and the Patriots joined the Giants, New Orleans, Tennessee, Houston, Washington, San Francisco, Buffalo and San Diego at 3-1.

The Saints, Super Bowl champions two years ago, labored to a 23-10 win over the Jacksonville Jaguars. Quarterback Drew Brees stretched his streak of throwing at least one touchdown pass to 31 games, the third longest in NFL history.

Matt Hasselbeck threw three touchdowns for Tennessee in a 31-13 win over the Cleveland Browns that snapped their six-game losing streak on the road and left them tied at the top of the AFC South standings with Houston.

The Texans posted a 17-10 win over the visiting Pittsburgh Steelers, last season's Super Bowl runners-up, who are 2-2 on the season. Arian Foster, starting for the first time after a hamstring problem, announced his return to the Houston lineup by rushing for 155 yards and a touchdown.

The Redskins rebounded from the disappointment of Monday's narrow loss to beat the St. Louis Rams 17-10 while the 49ers came from 20 points down to beat Philadelphia 24-23, despite Eagles quarterback Michael Vick throwing for a career-high 416 yards and running for another 75.