Seattle (4-0) rallied from a 17-point hole and won at Houston 23-20 in overtime on Steven Hauschka's 45-yard field goal.
"It was important for our ball club just to win on the road, just to continue our win streak," said cornerback Richard Sherman, whose interception return TD forced overtime. "I think that was important to us, to be that stepping stone, to continue to grow as a team."
Alex Smith threw three touchdown passes, Dexter McCluster returned a punt 89 yards for another score and Kansas City kept the New York Giants winless at 0-4 in a 31-7 rout.
"I know they'll battle," said Chiefs first-year coach Andy Reid, who spent the previous 14 seasons coaching the Eagles. "That's what I know. There are a lot of things I don't know but I do know this: We're a tough bunch."
New England staged a defensive stand after nearly frittering away a late lead and won at Atlanta 30-23.
"We are just griding it out," Tom Brady said. "4-0 is good, we certainly played better, got a lot to learn from."
Two more 3-0 teams, Miami and New Orleans, meet Monday night in the Big Easy.
Chicago fell from the undefeated ranks when it lost 40-32 at Detroit.
Week 4 began when San Francisco (2-2) beat St. Louis (1-3) 35-11 on Thursday night.
Green Bay (1-2) and Carolina (1-2) were off.
BRONCOS 52, EAGLES 20
At Denver, the Broncos set a team record for points they have been around 54 years with Manning's two TD passes each to Demaryius Thomas and Wes Welker. Manning even sat out the fourth quarter.
Manning also joined Milt Plum in 1960 as the only quarterbacks to throw 16 touchdown passes without an interception.
The Eagles (1-3) have allowed 138 points in four games.
SEAHAWKS 23, TEXANS 20, OT
At Houston, the Seahawks' first 4-0 start in franchise history was aided when Doug Baldwin caught a 7-yard pass and Kareem Jackson was penalized for unnecessary roughness for dumping him into the ground. That got Seattle in field goal range and Hauschka's kick came four plays later.
The Seahawks rallied to tie it at 20-20 on the pick-6 by Sherman in the fourth quarter.
Texans linebacker Brian Cushing sustained a concussion, and Seahawks coach Pete Carroll said defensive end Michael Bennett was OK after being taken off the field on a stretcher after injuring his lower back.
CHIEFS 31, GIANTS 7
Smith had touchdown passes of 4, 2 and 35 yards for the Chiefs, who under Reid have already doubled their victory total of 2012. They are the second team to go from a two-win season to 4-0 the next year, matching the 1980 Lions.
Smith was intercepted twice, the first giveaways by the host Chiefs, who also lost a fumble.
The Giants are 0-4 for the first time since 1987. Eli Manning connected with Victor Cruz on a 69-yard scoring play for New York's only score. The Kansas City defense sacked Manning three times.
PATRIOTS 30, FALCONS 23
At Atlanta, Brady threw for 316 yards and two touchdowns to improve the Patriots to 4-0 for the first time since their perfect regular season of 2007.
Strong defense in the red zone was decisive as Atlanta (1-3) had a chance to tie in the final minute. Matt Ryan's fourth-down pass went off the hands of Roddy White, tightly covered by Aqib Talib, in the end zone with 36 seconds remaining.
Rookie Kenbrell Thompkins finished with six catches for 127 yards, and Julian Edelman chipped in with 118 yards on seven receptions.
LIONS 40, BEARS 32
At Detroit, Reggie Bush's 37-yard touchdown run helped Detroit score 27 points in the second quarter. He accounted for 173 yards of offense as Detroit (3-1) moved into a first-place tie with Chicago (3-1) in the NFC North.
The Lions scored 24 straight points, including three TDs in a span of 3 minutes, 26 seconds, after Matt Forte's 53-yard TD run gave the Bears a 10-6 lead early in the second quarter.
Jay Cutler, who had four turnovers, threw a pair of touchdown passes and 2-point conversions in the final four minutes.
VIKINGS 34, STEELERS 27
At London, what looked like an international series dud between winless teams turned out quite entertaining.
Greg Jennings had two touchdown catches, Adrian Peterson ran for two scores and the Vikings' defense made a big stop with time running out at Wembley Stadium. Everson Griffen stripped Ben Roethlisberger at the 6-yard line with 19 seconds left. Kevin Williams recovered to seal the victory for Minnesota (1-3).
Jennings made a 70-yard catch-and-run for a touchdown and Peterson had a 60-yard score to help offset two scores by Pittsburgh rookie running back Le'Veon Bell.
The Steelers fell to 0-4 for the first time since 1968.
"Right now, you could say we're the worst team in the league," Roethlisberger said. "That hurts."
BILLS 23, RAVENS 20
Joe Flacco threw a career-worst five interceptions, and finished 25 of 50 for 347 yards and two touchdowns for the visiting Super Bowl champion Ravens (2-2).
Rookie linebacker Kiko Alonso's second interception of the game with 57 seconds remaining moved Buffalo to 2-2. Converted safety Aaron Williams also intercepted Flacco twice, while Fred Jackson had 87 yards rushing and a touchdown. Robert Woods scored on a 42-yard reception.
Torrey Smith had five catches for 166 yards and a 26-yard touchdown for the Ravens.
REDSKINS 24, RAIDERS 14
At Oakland, Robert Griffin III threw a go-ahead touchdown pass late in the third quarter to help Washington (1-3) overcome an early 14-point deficit. David Amerson returned an interception for another score.
Washington looked ready to extend the worst start for the franchise since 2001 when it fell behind 14-0 after the first quarter thanks to a blocked punt touchdown and a scoring pass from Matt Flynn.
But the much-maligned Washington defense allowed the Raiders (1-3) no more points. Oakland starting running backs Darren McFadden (hamstring) and Marcel Reece (knee) both left with injuries.
CHARGERS 31, COWBOYS 20
At San Diego, Philip Rivers threw for 401 yards and three touchdowns, including a 56-yarder to Antonio Gates.
The Chargers (2-2) had blown late leads in their two losses this season. However, they scored the final 20 points against Dallas.
Gates slid behind linebacker Sean Lee to score with 6:54 to go. Lee had intercepted Rivers on a deflected pass and returned it 52 yards for a touchdown and a 21-10 lead late in the second quarter. Dallas (2-2) didn't score again.
TITANS 38, JETS 13
At Nashville, before he left with a right hip injury that landed him in a hospital, Jake Locker threw a career-high three touchdowns. Locker was hurt early in the third quarter when hit first by Muhammad Wilkerson after throwing an incomplete pass, then popped by Quinton Coples. He grabbed at his hip as he went to the ground and was carted off the field before being loaded into an ambulance.
The Jets (2-2) yielded five sacks; Alterraun Verner intercepted two passes and recovered a fumble; Karl Klug sacked Geno Smith and stripped him of the ball for a TD; and the Titans (3-1) turned Smith's four turnovers into 28 points.
BROWNS 17, BENGALS 6
At Cleveland, Brian Hoyer threw two touchdown passes in his first start at home. Hoyer's 1-yard pass to Chris Ogbonnaya with 4:54 left gave the Browns (2-2) an 11-point lead that its vastly improved defense preserved. In his second start in place of injured Brandon Weeden, Hoyer finished 25 of 38 for 269 yards. He threw a 2-yard TD pass in the first half to Jordan Cameron, who had 10 catches for 91 yards.
Cleveland limited the Bengals (2-2) to 63 yards rushing.
COLTS 37, JAGUARS 3
At Jacksonville, the Jaguars' awful season continued as Andrew Luck threw two touchdown passes and Trent Richardson ran for a score.
Indianapolis (3-1) led 20-3 at halftime Jacksonville (0-4) has been outscored 75-8 in the first half this season and made it a laugher with consecutive touchdown drives in the third quarter.
Luck found Coby Fleener for a 31-yard score, then connected with Reggie Wayne in the back of the end zone from 5 yards.
CARDINALS 13, BUCCANEERS 10
At Tampa, Carson Palmer threw a 13-yard touchdown pass to Larry Fitzgerald, then Jay Feely kicked a 27-yard field goal with 1:29 remaining.
Patrick Peterson had two interceptions, one setting up Arizona's first TD in six quarters, the other to ruin any chance of rookie Mike Glennon pulling off a comeback in his first NFL start for the Bucs (0-4).
Feely also kicked a 42-yard field goal for the Cardinals (2-2), who trailed 10-0 at halftime.
Starting in place of the benched Josh Freeman, Glennon was steady until late in the game.
AP NFL website: www.pro32.ap.org