Colts 25, Texans 3: Andrew Luck threw two touchdown passes while Robert Mathis and Darius Butler made big plays defensively as host Indianapolis sent Houston to its 12th straight loss.

Luck was 19-of-32 for 180 yards and an interception that set up the Texans' only points late in the first quarter. Trent Richardson ran for 64 yards and had a short touchdown catch as the Colts (9-5) - who already have clinched the AFC South - improved to 5-0 in division play.

Case Keenum, who was named the starter for the rest of the season despite being pulled in his previous game, completed 18-of-34 passes for 168 yards with two interceptions. Running back Ben Tate had 92 total yards in the first game for Houston (2-12) since the firing of head coach Gary Kubiak.

Luck found Griff Whalen from 14 yards out on the opening drive to give the Colts the lead for good and shoveled the ball to Richardson for a 9-yard score and a 17-3 lead midway through the second. Butler made a pair of interceptions in the opening half and Adam Vinatieri hit the second of his three field goals to make it 20-3 going into the break.

Mathis set the franchise record for sacks in a season (16 1/2) and a career (108) - breaking Dwight Freeney's marks - on the same play when he got to Keenum in the end zone and knocked the ball free for a safety late in the third. Houston, which was outgained 331-239, had just four first downs in the second half.

GAME NOTEBOOK: Colts RB Donald Brown had 38 yards on five carries before leaving in the first half with a stinger. ... Houston committed 14 penalties for 114 yards after being flagged 14 times for a team-record 177 yards last week at Jacksonville. ... Indianapolis WR T.Y. Hilton made eight catches for 78 yards and Whalen finished with 45 receiving yards and 89 return yards.