Andrew Luck threw two touchdown passes and Donald Brown scored the go-ahead TD with 8:55 to go.
The Seahawks (4-1) lost their first regular-season game since last November 25.
Delano Howell scored on a 61-yard return of a blocked field goal for Indy (4-1).
Luck led his ninth career fourth-quarter comeback by going 16 of 29 for 229 yards, beating Russell Wilson in their first matchup.
Indy trailed 12-0 early, went ahead after Howell’s return, then rallied again to take the lead for good on Brown’s TD. The Colts sealed it with a 2-point conversion pass and a late field goal.
Wilson finished 15 of 31 for 210 yards with two TDs, one interception and ran 13 times for 102 yards.
Broncos 51, Cowboys 48
Matt Prater kicked a 28-yard field goal as time expired and Peyton Manning and Denver overcame the first 500-yard passing game in Dallas history to keep the Broncos unbeaten with a 51-48 victory over the Cowboys on Sunday.
Manning maintained his record pace of touchdown passes to start the season and finished with 414 yards and four scores for Denver (5-0).
Tony Romo threw for 506 yards and five touchdowns for Dallas (2-3), but he was intercepted by Danny Trevanthan inside the Dallas 30 to set up Prater’s winning kick.
The teams combined for 1,039 yards of total offence in the second-highest scoring game in regulation since the NFL-AFL merger in 1970, according to STATS.
Cincinnati and Cleveland combined for 106 points in the Browns’ 58-48 win in 2004.
Saints 26, Bears 18
Drew Brees threw two touchdown passes to Pierre Thomas, Jimmy Graham tied an NFL record with another 100-yard game and the New Orleans Saints remained unbeaten.
Brees was 29 of 35 for 288 yards in his first victory in four career games at Soldier Field. Garrett Hartley matched a career high with four field goals as New Orleans (5-0) picked up their first win in Chicago since a 31-10 victory on October 8, 2000.
Graham continued his torrid start for the Saints (5-0), catching 10 balls for 135 yards in his fourth consecutive 100-yard game – matching an NFL record for a tight end. Tony Gonzalez was the first to accomplish the streak in 2000, and Graham matched it in 2011.
Jay Cutler threw for 358 yards and two touchdowns for Chicago (3-2), who have lost two in a row.
Bengals 13, Patriots 6
BenJarvus Green-Ellis ran 1 yard in the fourth quarter for the game’s only touchdown, and the Cincinnati Bengals ended Tom Brady’s long streak of touchdown passes in defeating the previously unbeaten New England Patriots.
The Bengals (3-2) sacked Brady four times and kept New England (4-1) out of the end zone on a first-and-goal from the 1-yard line late in the fourth quarter.
Adam “Pacman” Jones picked off Brady’s desperation pass inside the 5-yard line with 16 seconds left to clinch it.
Brady had thrown a touchdown pass in 52 straight games, second-longest in NFL history behind Drew Brees. The Patriots were held out of the end zone for the first time since a 16-9 loss to the Jets on September 20, 2009.
Chiefs 26, Titans 17
Jamaal Charles scored a 1-yard touchdown with 6:23 left, and the Chiefs rallied to keep up their perfect start.
The Chiefs (5-0) are off to their best start since 2003, when they won their first nine games. This win came despite blowing a 13-0 halftime lead in this early AFC showdown between these surprising teams bouncing back after losing seasons.
The Titans (3-2) couldn’t have been more out of synch in the first half with Ryan Fitzpatrick starting for Jake Locker, sidelined with his sprained right hip. He missed his first five passes and went three-and-out on his first five series before guiding Tennessee to 17 straight points in the second half.
Charles put the Chiefs ahead to stay, and they intercepted Fitzpatrick twice in the final 6:14. Ryan Succop kicked four field goals, including a 48-yarder.
Ravens 26, Dolphins 23
Justin Tucker kicked a 44-yard field goal to put the Baltimore Ravens ahead with 1:42 left, and they withstood a frantic comeback bid.
Ryan Tannehill completed a 46-yard pass to Brandon Gibson on fourth down to keep Miami’s hopes alive, but Caleb Sturgis then missed a 57-yard field goal attempt wide left with 33 seconds to go.
The Ravens (3-2) bounced back from a loss last week at Buffalo and won on the road for the first time this season. The Dolphins (3-2) lost their second game in a row.
Baltimore moved 34 yards to set up Tucker’s game-winning field goal, his fourth of the day. The Ravens ran for a season-high 133 yards, and Joe Flacco threw for 269 yards.
Packers 22, Lions 9
James Jones caught a long touchdown pass from Aaron Rodgers, and the Packers defence contained the undermanned Lions.
Mason Crosby kicked five field goals. The Packers’ offence struggled to get into the end zone until Rodgers found Jones on an 83-yard completion down the left sideline for a 16-3 lead late in the third quarter.
It provided enough of a cushion for a defence that had the luxury of facing the Lions minus star receiver Calvin Johnson, out with a knee injury. Penalties also bogged down Detroit.
The Packers extended their winning streak in Wisconsin over the Lions to 23.
Eagles 36, Giants 21
Nick Foles threw for two touchdowns and led four scoring drives after taking over for an injured Michael Vick late in the second quarter, and Philadelphia kept the Giants winless.
Foles threw fourth-quarter touchdown passes of 25 yards to Brent Celek and 5 yards to DeSean Jackson as the Eagles (2-3) snapped a three-game losing streak by forcing three interceptions by Eli Manning in the fourth quarter.
Vick left the game with a hamstring injury late in the second quarter.
LeSean McCoy added a 1-yard touchdown run and Alex Henery kicked five field goals for the Eagles, who gained 439 yards in total offence.
David Wilson scored on a 5-yard run for the Giants (0-5) and Manning threw two touchdowns to Rueben Randle in the third quarter to give New York a 21-19 lead.
49ers 34, Texans 3
Tramaine Brock intercepted Matt Schaub’s first pass of the night and returned it 18 yards for a touchdown, setting San Francisco on course for a massive win over Houston.
Colin Kaepernick threw a 64-yard touchdown pass to Vernon Davis and Frank Gore ran for 81 yards and a score in his second straight impressive prime-time game.
The 49ers (3-2) are right back in the NFC West race with Seattle after the Seahawks (4-1) lost at Indianapolis. Each team has beaten the Texans (2-3) and lost to the Colts, and Seattle still must visit San Francisco on December 8.
Anthony Dixon added a 2-yard touchdown run for the NFC champions, while Brock had a second interception and nearly a third.
Cardinals 22, Panthers 6
Arizona sacked Cam Newton seven times, once for a safety, and intercepted him on three occasions to overcome a sluggish offensive performance.
Daryl Washington, back after serving a four-game suspension for violating the NFL’s substance abuse policy, had two sacks and an interception for Arizona (3-2).
Calais Campbell had two sacks, one for Arizona’s first regular-season safety in nine years, the other forcing a game-clinching fumble. Karlos Dansby also had two sacks and an interception.
Carolina (1-3), playing for the first time since a 38-0 victory over the New York Giants two weeks ago, managed only Graham Gano’s field goals of 22 and 51 yards.
Arizona’s Carson Palmer threw for a touchdown but was intercepted three times.
Rams 34, Jaguars 20
Sam Bradford threw three touchdown passes and Matt Giordano’s 82-yard interception return was one of several big plays from the St Louis defence against winless Jacksonville.
Austin Pettis’ 31-yard TD catch with 5:45 to go was his second of the day and put the Rams (2-3) up by two scores. St Louis, which had trailed by double digits in every game, established control with a 17-point second quarter after Jacksonville (0-5) had a pair of early leads.
Jaguars quarterback Blaine Gabbert injured his left hamstring in the third quarter. Rookie left tackle Luke Joeckel was carted off with a right ankle injury in the first.