HOUSTON — Two halves of football never looked so different.

In the first half of Sunday's Week 13 matchup between the Indianapolis Colts and the Houston Texans at NRG Stadium, both offenses came alive, particularly through the air, and the Colts went into the halftime break leading by four, 24-20.

The final two quarters, meanwhile, were a defensive slugfest — one in which the two AFC South Division rivals combined for just two points, six sacks and eight quarterback hits.

In the end, the Colts made one more big play — or, perhaps, made one fewer big mistake — than the Texans, however, and flew home with a dramatic 26-20 victory, improving their record to 8-4 on the season and, in the process, eclipsing their win total from the 2019 season.

"Wow — 60-minute game," Colts head coach Frank Reich said. "Really proud of the guys hanging in there. Great team win. We knew coming on the road against a division opponent who was hot, who could score some points, who has a special player at quarterback, it was going to require all three phases and we hung in there and did what we needed to do to win the game."

Much like last week's loss to the Tennessee Titans, Sunday's matchup against the Texans (4-8) had the makings of a shootout early on.

The Colts promptly went 67 yards in six plays on their first offensive drive, getting into the end zone with a 21-yard touchdown pass from Philip Rivers to T.Y. Hilton to make it 7-0 with 9:59 left in the first quarter. The Texans answered right back, going 75 yards in just four plays on their ensuing drive, as quarterback Deshaun Watson ran it in from 11 yards out to tie the game at 7 with 7:56 left in the opening period.

A Texans field goal briefly gave them the lead, 10-7, before the Colts answered right back with an eight-play, 72-yard drive that ended with a five-yard touchdown run by Nyheim Hines, putting them back on top, 14-10.

And that was just the first quarter.

After a missed field goal attempt by the Texans' Ka'imi Fairbairn early in the second quarter, Reich took a big gamble on 4th and 4 from the Houston 39-yard line; Houston had a man-to-man look defensively on the play, but the only man they didn't account for was running back Jonathan Taylor, whom Rivers found wide open for a 39-yard touchdown, giving the Colts a 21-10 lead with 9:24 left in the second quarter.

But Watson and the Texans, as they're known to do, just wouldn't go away. Taking advantage of a defensive holding call on 3rd and 12 from the Indy 15-yard line, running back David Johnson would promptly run it into the end zone from six yards out to pull Houston back within four, 21-17.

The two teams would trade field goals to end the second quarter, as the Colts went into the halftime break leading 24-20.

Indy's passing offense was on fire over the first two quarters on Sunday, as Rivers completed 19-of-23 pass attempts for 209 yards with two touchdowns for a 133.5 quarterback rating over that span; Hilton, meanwhile, continued his dominance of the Texans at NRG Stadium, as he had seven first-half receptions for 100 yards and his aforementioned 21-yard score.

"Yeah, I feel like we've said it all year long: it's just a matter of time till he really gets rolling," Rivers said of Hilton.

Neither team's offense could really get on much of a roll in the second half of Sunday's game, however.

The Colts' defense really picked up the pace, particularly, over the final two quarters; they sacked the elusive Watson three times, forced two turnovers and a safety and allowed just three yards per run after allowing more than six yards per rush in the first half.

Indy's offensive and special teams units, either due to poor execution or untimely penalties, couldn't get out of their own way during that same span, meanwhile.

Kenny Moore II would get his third pick of the season with 1:02 left in the third quarter — Watson's first interception thrown since Week 5 — but the Colts would go three-and-out on the ensuing drive.

On the Colts' next offensive drive — really, their best sequence of the second half — they got all the way to the Houston 5-yard line before facing a 4th-and-1 scenario. Reich continued to keep his foot on the gas pedal and elected to go for it vs. kicking a chip-shot field goal that would've given Indy a 27-20 lead with 6:50 left in regulation, but Hines was stuffed for no gain and a turnover on downs.

Indy's defense came through once again on the next Texans drive, as Justin Houston brought down Watson in the end zone; it was his third sack of the day and his NFL record-tying fourth forced safety of his career, and it gave the Colts a 26-20 lead with 6:08 left in the fourth quarter.

Hines then nearly took the ensuing safety punt to the house for a game-sealing touchdown, but a holding call brought the ball all the way back to the Indianapolis 25-yard line. The Colts got to the Houston 49-yard line before another holding call put the offense out of phase, and Indy would be forced to punt a few plays later, giving the ball back to Watson & Co. at their 20-yard line, trailing by six with 2:43 left on the clock.

Despite not having the services of his top receiver, Will Fuller V, who was suspended for the remainder of the season earlier in the week, Watson methodically worked the Texans' offense down the field, getting completions of nine, 23, 18, eight, and 16 yards, respectively, on five straight passing plays to get to the Indianapolis 6-yard line.

Duke Johnson ran it for four yards on 1st and Goal from the 6, and a go-ahead Texans touchdown and extra point seemed imminent at this point.

But on 2nd and Goal from the 2, everything suddenly came unraveled for the Texans — to the delight of the Colts' sideline.

Watson couldn't handle a low snap from center Nick Martin, and defensive tackle Grover Stewart flew in to ensure the quarterback couldn't get his hands on the loose ball, which was quickly recovered by Walker for the huge takeaway; all Rivers had to do from there was kneel it out to complete a dramatic Colts road win.

"Yeah, that was crazy," Reich said of the Texans' botched snap at the end of the game. "Obviously, that's why it's a 60-minute game. …We got the break there. We made the break. They dropped a snap. We had a good recovery, guys hustling to the ball, getting it on our side. Certainly take it any way we can get it."

Rivers, in all, completed 27-of-35 passes for 285 yards with two touchdowns for an overall QB rating of 119.3; Hilton led the way with eight receptions for 110 yards and a touchdown, as he was one of nine Colts receivers to haul in a pass on the day.

Taylor had a solid all-around day for Indy, as the rookie running back led the way with 13 rushing attempts for 91 yards (7.0 avg.) and also had three receptions for 44 yards and his 39-yard touchdown grab.

Walker led the Colts' defense with 10 tackles, a pass defensed and a fumble recovery, while Houston turned in a big performance with four tackles, three sacks and a forced fumble. Defensive tackle DeForest Buckner added four tackles, two sacks and three quarterback hits, while Moore II had eight total tackles and three passes defensed to go along with his third pick of the season.

Watson completed 26-of-38 passes for 341 yards, but was held without a passing touchdown and was intercepted once. Keke Coutee continued to be a thorn in the Colts' side, as he finished the day with eight receptions for 141 yards, while Chad Hansen had a career day with five receptions for 101 yards.

The Texans were held to just 90 yards rushing on the day, led by David Johnson's 10 carries for 44 yards and a touchdown.

Defensively, linebacker Tyrell Adams had a game-best 12 total tackles; defensive end J.J. Watt had five tackles, four of which were for a loss, including a sack.

Sunday's win for the Colts keeps them in the driver's seat for a playoff spot with four games now left to play. Next week they head to Las Vegas to take on a 7-5 Raiders team in yet another pivotal AFC matchup.

"We've got to learn from this game, be excited about this win. Any division road win is big," Rivers said. "Then we put all our attention on the Vegas Raiders and find a way to go 1-0 this week, (and) not get caught up in what could happen over the next four weeks, because who knows — who knows what's going to happen? We've just got to control what we can control."