Nashville, TN (SportsNetwork.com) - Five games, five wins for the Kansas City Chiefs.

A season after tying the worst record in franchise history, the Chiefs are off to their best start in a decade.

Who saw that coming?

Jamaal Charles scored the go-ahead touchdown on a 1-yard run in the fourth quarter and the Chiefs beat the Tennessee Titans 26-17 on Sunday.

The Chiefs (5-0) coughed up a 13-0 first-half lead -- built in part by Marcus Cooper's touchdown on a muffed punt -- but scored 13 unanswered points to end the game, keeping coach Andy Reid unbeaten with his new team.

"This was a resilient win," said Reid. "Guys stepped to it in a game with a lot of ups and downs. ... When we went down in the second half, the eyes I'm looking into are positive eyes."

Charles rushed for 108 yards and Alex Smith passed for 245. Charles' go-ahead touchdown came after a 15-yard unnecessary roughness penalty on Tennessee linebacker Moise Fokou, who hit Smith as he was running out of bounds on a third-down play.

The Chiefs then intercepted Ryan Fitzpatrick on two straight drives -- Cooper had one -- turning the picks into field goals by Ryan Succop, who kicked four in the game.

Fitzpatrick started for Jake Locker, who will miss a few weeks with a sprained hip. The former Bills starter passed for 247 yards and one touchdown -- Chris Johnson's slashing 49-yard catch-and-run.

Fitzpatrick also rushed for a score that gave the Titans (3-2) a 17-13 lead on the first play of the fourth quarter, but they never scored again.

On Fitzpatrick's two late interceptions, Cooper wrestled the ball away from Nate Washington near the sideline and Quintin Demps caught a tipped pass.

"This was kind of a roller-coaster ride," said Titans linebacker Zaviar Gooden. "We've just got to finish games."

Earlier, Cooper fell on the ball for a touchdown after it hit off Tennessee's Damian Williams and bounced about 20 yards into the end zone on a Kansas City punt.

The Chiefs, after going 2-14 last season, are 5-0 for the first time since they started 9-0 in 2003.

They almost let this one get away.

Johnson was a blocker on the right side on the play that ended in his 49-yard touchdown in the third quarter. He fell down on the block, popped up, caught the passed and cut through the middle of the field to the left sideline to get the Titans within 13-7.

Rob Bironas' 22-yard field goal made it a three-point game, and Fitzpatrick's 9-yard touchdown run on third down gave the Titans the lead.

Smith scrambled to the right sideline and was going out of bounds short of a first down when Fokou dove and knocked the quarterback down, drawing a 15-yard penalty and moving the Chiefs to the Tennessee 27.

Dwayne Bowe's 7-yard catch took Kansas City to the goal line and Charles broke through the left side to make it 20-17.

Cooper picked off Fitzpatrick on the first play of Tennessee's ensuing drive, jumping in front of Washington. That led to a 33-yard Succop field goal. Demps then intercepted a tipped pass at the Kansas City 32 and took it back 35 yards and Succop drilled a 48-yarder to make it 26-17 for the final margin.

"We're built for this," said Chiefs cornerback Brandon Flowers. "The last few years we've been through every kind of adversity you can imagine. ... Being 5-0 is lots of fun, especially after last year."

Replays showed Titans return man Darius Reynaud tried to wave off Williams as Dustin Colquitt's punt landed inside the 25-yard line. But the ball hit off Williams' heel near the 22 and shot back toward the end zone.

Cooper beat Williams to the ball and jumped on it, giving the Chiefs a 7-0 lead just over three minutes into the game.

The teams traded punts until Succop's 29-yard field goal for the Chiefs to open the second quarter.

The Titans did nothing after a Charles fumble and punted. On their next drive, Jackie Battle was stuffed in front of the goal line on fourth down and the Chiefs turned around and took a 13-0 lead on Succop's 24-yard field goal.

Game Notes

Smith was 20 of 39 passing and Fitzpatrick went 21 of 41 ... Charles had 22 rushing attempts and five catches for 37 yards ... Chiefs wide receiver Donnie Avery had three catches for 91 yards ... Johnson rushed 10 times for just 17 yards and Fitzpatrick ran six times for 50 ... Kansas City played without No. 1 draft pick Eric Fisher. The right tackle sat out with a concussion ... The Chiefs play the Raiders at home next Sunday ... The Titans have a tough test in Seattle ... The Chiefs failed to reach five wins four times in the last nine seasons.