HOUSTON -- Undermanned, overwhelmed and at one point down 17 points to the Houston Texans, weary Indianapolis Colts defenders went to the half gratified that there were still two quarters to play Sunday afternoon.
"We've never been taught to play a 30-minute game," said Colts weakside linebacker Clint Session, a hero in Indianapolis' 35-27 victory that kept his team perfect through 11 games. "We're a 60-minute team. We're always confident that, if we just play our game, things will come around."
Session's 27-yard interception return of a Matt Schaub pass helped give the Colts a 28-20 cushion with 8 minutes, 9 seconds remaining. The play was a highlight of 21 unanswered Colts points in less than six minutes in the fourth quarter, a feat made even more remarkable considering Indianapolis' defense is minus five starters (including three in the secondary).
The successful rally -- combined with the Jacksonville Jaguars' loss to the San Francisco 49ers -- allowed the 11-0 Colts to clinch the AFC South title for rookie head coach Jim Caldwell. Indianapolis established an NFL record by winning at least 11 games for the seventh year in a row. The Texans lost for the third straight time and dropped to 5-6, including 2-4 at Reliant Stadium.
Houston seemed set on avenging a 20-17 Week 9 loss at Indianapolis. In the first half of the rematch, the Texans' offense scored on its first four possessions, racking up 16 first downs and 242 yards. The Colts trailed 17-0 before they knew what hit them. Houston led 20-7 at the half.
Somehow the Colts stormed back and outscored the Texans 28-7 in the second half. Houston wilted as it almost always has against the Colts, losing for the 15th time in the series' 16 games.
"We've always been resilient, but this might be the most [resourceful] we've ever been," said defensive end Robert Mathis, who collected a fourth-quarter sack-and-strip of Schaub. "We find a way to win, no matter who is out there for us."
The takeaway led to Chad Simpson's 23-yard touchdown run with 2:52 remaining that helped give the Colts a 35-20 lead.
Mathis' strip of Schaub was another instance of the injury-plagued defense making timely plays. The Colts were without cornerbacks Marlin Jackson and Kelvin Hayden, star strong safety Bob Sanders, strongside linebacker Tyjuan Hagler and right defensive end Dwight Freeney, whose abdominal injury made him a Saturday evening scratch. Sanders, the league's defensive most valuable player in 2007, and Jackson are both on injured reserve for the season.
In the first half, the Texans exploited a Colts defense featuring a pair of rookie cornerbacks, and nine players in all with fewer than four seasons of previous NFL experience.
In the second half, though, the Colts toughened. They did not allow a second-half Houston touchdown until 18 seconds remained in the game. The Colts blitzed more than usual, especially in the second half, and exerted solid pressure on Schaub, who was sacked twice in addition to committing three turnovers.
On its first five offensive forays in the second half, Houston had two punts, a pair of Schaub interceptions and a Schaub fumble. The Texans, who outgained the Colts for the game (396-342), netted only 154 yards on 32 second-half snaps.
"The thing is, we don't panic, we don't scream, we don't throw helmets," said Colts quarterback Peyton Manning, who threw two first-half interceptions (the third straight game in which he has suffered a pair of pickoffs). Manning threw two scoring passes in the second half, including a 6-yarder to tight end Dallas Clark that helped give the Colts a 21-20 lead.
"We just figure that we've dug ourselves a hole, and we've got to do whatever it takes to dig ourselves out."
Manning helped excavate the Colts with a quick-snap call early in the fourth quarter, which resulted in a 31-yard completion to rookie wide receiver Austin Collie. The snap came while the Texans were still lining up. The play moved Indianapolis off its own 15-yard line, and sparked the 89-yard drive that culminated in Clark's touchdown with 8:24 left in the fourth period.
Just 15 seconds after Clark's score, Session stepped in front of a Schaub pass intended for James Casey over the middle, and sprinted up the right sideline for the score.
"It's frustrating. Everything was right there for us. … Then it got into the fourth quarter, and we kept hurting ourselves," said Schaub, who finished 31-for-42 for 284 yards, after completing 10 of his first 11 passes.
The win marked the second season in a row in which the Colts rallied from a 17-point deficit at Reliant Stadium. But coming back from early deficits, both big and small, has become a hallmark of an Indianapolis team that won its first six games by an average of 17.0 points. The Colts have won their past five games by 4, 3, 1, 2 and 8 points. In fact, the Colts became the first team in league annals to win five straight games after trailing in the fourth quarter of all of them.
Indianapolis has now won 10 straight road games and 20 consecutive games overall. The 20 victories are one shy of the New England Patriots' NFL-record 21-game run from 2006 to '08. The Colts can tie the record if they beat the resurgent Tennessee Titans at Lucas Oil Stadium next weekend.
Observers have been insisting the past few weeks that the Colts' lack of manpower, particularly on defense, will catch up to them. But so far, Indianapolis has ignored the skeptics and remained oblivious to some dicey situations.
"We know the script pretty well," said middle linebacker Gary Brackett. "I mean, we've certainly rehearsed it enough times, right? As much as we'd all love a breather, these [close] games build character. And right now, we're a team with great character."
Len Pasquarelli is a senior writer for ESPN.com.