Alex Smith connected with Delanie Walker for a fourth-down scoring pass with less than two minutes left to lift San Francisco to a 25-19 win over previously unbeaten Detroit in the NFL on Sunday. The six-yard touchdown toss stood up after a video review, and Detroit could not get a first down against the determined 49ers defense as they tried desperately but in vain to respond. San Francisco and the Lions are the surprise teams of the season, and their marquee match-up was a back-and-forth battle. The 49ers overcame a 19-15 fourth-quarter deficit as well as a season-high 15 penalties in front of an incredibly loud Detroit crowd of 62,061. They will take their first four-game winning streak since 2001 into their bye week. \"It\'s amazing to see the transformation we\'ve become since Day One,\" linebacker Patrick Willis said. \"We know that no matter what happens, we\'ll continue to fight.\" The exciting contest featured five lead changes, but the action was almost overshadowed by an odd squabble between the opposing coaches after it ended. Niners coach Jim Harbaugh and Lions coach Jim Schwartz had to be separated by players, security and public relations officials after their post-game hand-shake devolved into a near fight. Harbaugh accepted the blame for what he called \"kind of a slap-grab handshake\". \"I was just really revved up, and it\'s totally on me,\" Harbaugh said. \"I shook his hand too hard.\" Schwartz said Harbaugh yelled an expletive in his ear. \"I think there\'s a protocol that goes with this league,\" said an indignant Schwartz, who pursued Harbaugh as he walked away and purposely bumped into him. With the Lions\' defeat, Super Bowl champions Green Bay remained the league\'s only unbeaten team, notching a 24-3 victory over hapless St. Louis. Aaron Rodgers threw three touchdowns, including a career-long 93-yarder to Jordy Nelson as the Packers improved to 6-0. New England\'s superstar quarterback Tom Brady rallied the Patriots to a 20-16 victory over Dallas, completing an eight-yard touchdown pass to Aaron Hernandez with 22 seconds remaining. In Oakland, Jacoby Ford returned a kickoff 101 yards and Kevin Boss caught a 35-yard touchdown pass on a fake field goal to lead the Raiders to a 24-17 victory over Cleveland in their first home game since the death of owner Al Davis. Amid moving ceremonies to honor Davis, a sour note was sounded as Raiders quarterback Jason Campbell broke his right collarbone when he landed hard on his shoulder on a hit from two Cleveland defenders. In other games, Baltimore beat Houston 29-14, Atlanta defeated Carolina 31-17, Chicago beat Minnesota 39-10 and Pittsburgh downed Jacksonville 17-13. The New York Giants edged the Buffalo Bills 27-24 and Tampa Bay defeated New Orleans 26-20, snapping the Saints\' four-game winning streak. It was an especially painful loss for Saints coach Sean Payton, who suffered a torn ligament and broken bone in his left leg when a player fell on him on the sideline. Michael Vick threw for 237 yards and a touchdown and Kurt Coleman grabbed three interceptions for Philadelphia in a 20-13 victory over Washington. Cincinnati\'s Nate Clements blocked a late field goal attempt that would have tied the game and Carlos Dunlap returned an Indianapolis fumble 35 yards for the decisive score as the Bengals beat the Colts 27-17. The Colts, without injured star quarterback Peyton Manning, have yet to win this season.