KANSAS CITY, Mo. (AP) -- Jamaal Charles carried the Kansas City Chiefs to another victory.
His defense helped shoulder the load once again.
Charles ran for 86 yards and a touchdown, Alex Smith also ran for a score and the scrappy Chiefs held off the banged-up Houston Texans 17-16 on Sunday to remain unbeaten.
The Chiefs were forced to punt the ball to Houston with 1:46 left in the game.
But after Case Keenum threw an incompletion on first down, the young quarterback was stripped by linebacker Tamba Hali at his 2. Derrick Johnson recovered the fumble for the Chiefs.
Smith simply kneeled on it from there as time ran out, allowing Kansas City (7-0) to extend the second-best start in franchise history. The 2003 team began the season 9-0.
Keenum, making his first NFL start in place of the injured Matt Schaub, threw for 271 yards and a touchdown for the Texans (2-4).
But he didn't get much help from his run game after Arian Foster left in the first quarter with a hamstring injury and did not return.
Ben Tate, who also briefly left with an injury, had just 50 yards rushing for Houston.
The Chiefs' defense, which led the NFL in scoring coming into the game, continually made big plays.
They held the Texans to a field goal after facing first-and-goal at the 1-yard line in the third quarter, and then kept turning Houston back on every series in the fourth quarter.
Charles finished with 123 yards from scrimmage, joining O.J. Simpson as the only players in NFL history with at least 100 yards from scrimmage and a touchdown in the first seven games of a season. Simpson did it in the first nine games of the 1975 season.
The Texans opened the scoring on Randy Bullock's 48-yard field goal, but the drive proved costly when Foster left for the locker room. When he emerged a short while later, he was wearing a gray sweatsuit and his afternoon was done.
The Chiefs answered with an 82-yard drive that was helped along by a roughing-the-passer penalty on Texans defensive end Jared Crick. Charles did most of the work on the drive, so it was only fitting that he plunged in from a yard to give Kansas City a 7-3 lead.
Keenum, clearly unperturbed by the crowd inside Arrowhead Stadium, calmly guided Houston back into the lead. He hit DeVier Posey for a 42-yard reception, and then found DeAndre Hopkins - who had run right past cornerback Sean Smith - for a 29-yard touchdown reception.
The Texans still led 10-7 when they pinned Kansas City at its 3-yard line midway through the second quarter. Smith proceeded to guide the Chiefs 97 yards in 15 plays - he was 8 of 8 for 75 yards on the drive - and used all but 56 seconds on the clock to regain the lead.
Smith scored on a 5-yard draw when he froze the defense on a fake handoff to nobody.
Bullock tacked on two more field goals for Houston, and Ryan Succop hit one for the Chiefs, who came within inches of extending their 17-16 lead early in the fourth quarter.
Tight end Anthony Fasano caught a pass at the goal line and was ruled down, and Chiefs coach Andy Reid challenged the spot to no avail - he thought it was a touchdown.
Charles was stuffed on the next play, and Smith's pass to wide open Sean McGrath on fourth down was out of bounds.
It turned out that it didn't matter. The Chiefs' defense made sure of that.