INDIANAPOLIS — Another slow start. Another Andrew Luck-led Indianapolis Colts victory.

The AFC South-leading Colts turned the ball over on their first two possessions and three times during the first two quarters Sunday in Lucas Oil Stadium but had more than enough to defeat the struggling Washington Redskins 49-27.

Luck threw first-half touchdown passes of 30 yards to tight end Colby Fleener and 3 yards to wide receiver T.Y. Hilton, and running back Daniel Herron ran 49 yards for a second-quarter TD as Indianapolis grabbed a 21-10 halftime lead. Luck finished 19 of 27 for 370 yards and a career-best five touchdowns.

Redskins quarterback Colt McCoy, who replaced Robert Griffin III as the team’s starter this week, was 31 for 47 for 392 yards, three touchdowns and no interceptions.

The Colts (8-4) drove 83, 80 and 68 yards for first-half touchdowns, seizing a 21-3 lead with 6:53 remaining in the second quarter.

Washington (3-9), which has lost four in a row, scored only three points as the result of a Luck fumble on the game’s first snap from center and a Ryan Clark interception of a Luck pass the second time Indianapolis had the ball.

The Redskins pulled within 21-10 with 1:59 remaining in the second quarter on McCoy’s 21-yard touchdown pass to running back Roy Helu Jr., capping a nine-play, 84-yard drive.

Washington continued to apply the pressure with the first possession of the third quarter, getting a 16-yard touchdown pass from McCoy to right end Logan Paulsen at the 11:22 mark. The Redskins went 89 yards in eight plays to close to within 21-17.

Indianapolis needed only three plays to answer the Washington score, getting a 48-yard touchdown pass from Luck to wide receiver Donte Moncrief with 10:05 left in the third period, extending its advantage to 28-17.

The Colts got what proved to be the game-clinching TD with 7:30 remaining in the third quarter when middle linebacker D’Qwell Jackson scooped up a McCoy fumble at the Washington 35-yard line and ran untouched for the score that extended the Indianapolis lead to 35-17.

The Redskins faced fourth-and-inches on the McCoy fumble and opted for a play-action pass that backfired.

McCoy came back to throw his third touchdown pass, a 42-yarder to wide receiver DeSean Jackson with 5:12 to go in a high-scoring third quarter, trimming the deficit to 35-24. That Redskins drive covered 80 yards in six plays.

The wild third quarter continued with Luck’s fourth touchdown pass, a 73-yarder to college teammate Fleener with 4:45 on the clock. At that point, Indianapolis led 42-24.

A 29-yard Kai Forbath field goal with 12:00 left in the fourth quarter pulled the Redskins within 42-27.

Luck threw his fifth touchdown pass with 10:34 remaining, connecting on a 79-yard scoring play over the middle to a wide open Moncrief for a 49-27 lead. That brief three-play drive covered 80 yards.

NOTES: Indianapolis improved to 5-2 in Lucas Oil Stadium, losing only to Philadelphia and New England … The Colts lost CB Vontae Davis with a concussion in the third quarter … Inactive for Indianapolis were TE Weslye Saunders, OLB Andy Studebaker, G Lance Louis, G Hugh Thornton, T Xavier Nixon, TE Dwayne Allen and NT Zach Kerr … The Redskins’ inactives were QB Kirk Cousins, WR Aldrick Robinson, CB E.J. Biggers, G Spencer Long, DE Stephen Bowen, T Tyler Polumbus and WR Leonard Hankerson … Muncie, Ind., native and former Purdue University standout OLB Ryan Kerrigan suffered a third-quarter wrist injury for the Redskins and missed the rest of the game … The teams combined for 35 third-quarter points … Indianapolis has only one more regular-season home game, an AFC South date with the Houston Texans on Dec. 14 … Colts QB Andrew Luck completed only two third-quarter passes in three attempts, but each completion was a touchdown … Redskins QB Colt McCoy was 15 of 18 for 205 yards and two touchdowns in the third period, compiling a passer rating of 151.2