Alex Smith was 23-of-34 for 240 yards and an interception and added a rushing touchdown as the Chiefs improved to 7-0 for the first time since winning their first nine games in 2003.

Case Keenum went 15-for-25 for 271 yards and a touchdown in his first career start for Houston (2-5), and played turnover-free until a fumble on the Texans' final possession. Andre Johnson had four catches for 89 yards and DeAndre Hopkins caught three balls for 76 yards and a TD.

Hopkins hauled in a 29-yard touchdown pass from Keenum on the first play of the second quarter to give Houston its only lead at 10-7. Smith's 5-yard run capped a 15-play, 97-yard drive to give the Chiefs a 14-10 advantage at halftime.

The teams traded field goals in the second half, and Randy Bullock's third of the day pulled Houston within one with 4:21 left in the third quarter before the Chiefs turned up the defensive pressure and held the Texans scoreless the rest of the way. Kansas City sacked Keenum four times in the fourth quarter, including Tamba Hali's hit and forced fumble that allowed it to run out the clock.

GAME NOTEBOOK: Texans RB Arian Foster (hamstring) left during Houston's first series and LB Brian Cushing was carted off with a left knee injury in the third quarter. … Charles also had three catches for 37 yards and has reached 100 yards from scrimmage in every game this season. … The Chiefs are the only team in the league that has not allowed more than 16 points in a game.