The last time the Kansas City Chiefs trailed at halftime, they lost the AFC championship to the New England Patriots.

On Sunday, the Indianapolis Colts carried a 13-10 lead into halftime and executed a near-perfect gameplan in the second half to stun Kansas City, 19-13, handing the Chiefs their first loss of the season.

The Colts offensive line controlled the line of scrimmage and the game, keeping the ball out of Kansas City quarterback Patrick Mahomes’ hands for most of the second half. When he had the ball, Mahomes was mostly ineffective thanks to relentless pressure from the Indianapolis defense and a left ankle injury that appeared to limit his mobility.

Old-school football tops NFL’s most dynamic offense

It was a victory for Frank Reich’s throwback, grind-it-out football over Andy Reid’s high-octane offensive attack led by the game’s most dynamic young quarterback and defending league MVP.

Indianapolis ran the ball 45 times for 180 yards and held the ball for 37 minutes compared to Kansas City’s 23. When the Chiefs had the ball, the Colts were constantly on attack, sacking Mahomes four times for a loss of 33 yards. Prior to Sunday, Mahomes had been sacked just three times in four games.

The decisive sequence of the game wasn’t a potent display of offense from the Colts, but an example of precise execution of a gameplan to limit the effectiveness of juggernaut Chiefs offense.

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Holding a 13-10 lead with 2:30 remaining in the third quarter, the Colts elected to punt on fourth-and-seven from Kansas City’s 41-yard line.

Mahomes tweaks ankle

The Chiefs took over at their own five-yard line. Two Mahomes incompletions and a Damien Williams run for no gain later, and the Chiefs were forced to punt out of their own end zone. At the end of the drive, Mahomes limped off the field after having his already-taped left ankle stepped on by a teammate during his third-down drop back.

Mahomes initially twisted the ankle during the first half — the same ankle that forced him to miss some plays in Kansas City’s season opener against the Jacksonville Jaguars.

Colts dominate ball late

What the Colts did next wasn’t pretty. But it was effective. After taking over on the punt at the Kansas City 48-yard line, Indianapolis ran 14 plays for 35 yards, eating 8:34 off the clock. The drive didn’t end in a touchdown, but an Adam Vinatieri field goal to take a 16-10 lead with 7:43 remaining.

The Indianapolis defense did its job once again on the next Chiefs possession that gained eight yards on five plays and ended with former Justin Houston stuffing Williams in the backfield on fourth-and-one at Kansas City’s 34-yard line in a certainly satisfying moment for the former Chief who was cut this spring in a salary dump despite being one of the league’s most effective pass rushers.

“I didn’t like the way things ended when I left here,” Houston told NBC after the game. “To come back and get a win, it mans so much to me.”

Houston ended the night with four tackles, a sack and the biggest defensive play of the game.

The Colts scored another Vinatieri field goal on their ensuing possession for a two-possession lead that proved too much for Mahomes and the Chiefs to overcome on a last-ditch drive that ended in a field goal. When their onside kick failed, the game was over.

Mack outshines Mahomes

Marlon Mack was a frequent star of the Colts grinding game plan, running 29 times for 132 yards behind a bullying offensive line. The Chiefs, by comparison, gained just 36 total rushing yards on 14 attempts the entire game.

Mahomes finished the game completing 22-of-39 pass attempts for 321 yards with a touchdown and no turnovers. He opened the game with a few of the trademark plays that made him the NFL MVP last season, including a remarkable 27-yard touchdown pass to Byron Pringle after escaping pressure form the Colts front four. He threw for 130 yards in the first quarter.

It’s hard to attribute how much his ankle bothered him and how much of his play was strictly due to the Colts defense, but he was largely ineffective after halftime.

With the win, the Colts improve to 3-2, while the Chiefs fall to 4-1.

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