Andrew Luck paced an efficient offense and the visiting Indianapolis Colts continued their torrid play, defeating the Houston Texans 21-7 on Saturday in an AFC wild-card playoff game.With the win, the sixth-seeded Colts will face the top-seeded Kansas City Chiefs next Saturday at 4:35 p.m. ET at Arrowhead Stadium.Luck finished 19 of 32 for 222 yards and two touchdowns as the Colts, who won nine of their last 10 regular-season games to clinch a playoff berth, earned their first postseason win since the 2014 divisional round. Indianapolis finished 9 of 14 on third downs, including 6 for 6 in the first half en route to a 21-0 lead.That third-down prowess yielded three touchdowns over the opening four possessions, with the Colts’ third drive concluding in the red zone after Texans nose tackle Brandon Dunn picked off a pass deflected by defensive end J.J. Watt. Trailing 14-0 early in the second quarter, the Texans managed only 4 yards on the ensuing possession before punting from their 19.Luck, having already engineered scoring drives of 75 and 74 yards, briskly covered 65 yards in seven plays. That march culminated in a Dontrelle Inman 18-yard touchdown catch to make it 21-0 with 6:24 left in the half. A snap before the touchdown, Texans rookie safety Justin Reid separated tight end Eric Ebron from the ball in the end zone, momentarily preventing the Colts from taking a three-score lead.The Texans were undone by mental miscues and an unexpectedly inaccurate showing from quarterback Deshaun Watson, who made his postseason debut. Watt and Whitney Mercilus were both flagged for neutral-zone infractions on third down in the first half, enabling the Colts to convert on third-and-short on drives that ended in touchdowns: A Luck-to-Ebron 6-yard pass at the 10:32 mark of the first, and a 2-yard run by Marlon Mack with 4:03 left in that quarter.Mack rushed for 148 yards on 24 carries. T.Y. Hilton added five catches for 85 yards, including three receptions for 63 yards on the opening possession. Indianapolis amassed 422 total yards and did not surrender a sack, as the Texans hit Luck just four times.With Houston trailing 14-0, Watson misread the coverage on fourth down and tossed an interception to Colts cornerback Kenny Moore, who undercut Ryan Griffin. It was one of three fourth-down failures by Houston.