Indianapolis tight end Dallas Clark (44) is stopped by Houston Texans linebacker Brian Cushing (56) and DeMeco Ryans during the third quarter of the Colts comeback win. (David J. Phillip/Associated Press)

Peyton Manning threw for three touchdowns and the Colts rallied from 17 points down for a 35-27 road win over the Houston Texas, preserving their unbeaten record and locking up a playoff spot.

It was the team's 20th straight regular-season victory dating back to last season. Indianapolis (11-0) is one win shy of the New England Patriots' NFL-record 21-game run from 2006-08.

The Colts can tie the record if they beat Tennessee at home next weekend.

Indianapolis clinched their sixth AFC South title in seven years a few hours later on Sunday when the Jacksonville Jaguars lose to the San Francisco 49ers. The Colts are the first NFL team this season to lock up a playoff berth.

"We don't get overexcited certainly when things aren't going the way we want them to," Manning said. "We don't panic, we don't yell, we don't throw helmets. We just try to put the series behind us and move on to the next one. There was a lot of that [today]."

For Houson (5-6), the result was eerily similar to their home game against the Colts on Oct. 5, 2008, when Indianapolis stunned them 21 points in just over two minutes late in the fourth to snatch victory away.

"This isn't the first time this has happened to us," Texans receiver Andre Johnson said. "It's just real frustrating. I'm very upset with myself. It's kind of sounding like a broken record, we've just got to find a way to play for four quarters."

Indianapolis improved to 15-1 all-time against the Texans.

With the score 21-20 Indianapolis six minutes into the fourth, Houston quarterback Matt Schaub threw an ill-advised pass that Clint Session returned 26 yards for a touchdown.

On Houston's next possession, Colts defensive lineman Robert Mathis made a tremendous play, swatting the ball out of Schaub's hand as he reared back to throw, causing an another turnover.

Colts running back Chad Simpson then bounced off three would-be tackler en route to a 23-yard touchdown run.

"That's a good team over there, but we're the Colts," Session said. "We do things the right way and we try to get every win we can get."

Jacoby Jones caught a touchdown pass from Schaub to close the gap, but there was just 18 seconds remaining. Houston tried an onside kick, but it was off the mark, sealing the deal.

Manning threw two first-half interceptions, but had a pair of second-half TD passes, including a four-yarder to Dallas Clark that gave the Colts a 21-20 lead with about nine minutes left.

Houston, which has lost three straight, was all but unstoppable in the first half, and the Texans scored on their first four possessions. It was a different story after halftime, with the

Houston scored on its first possession for the first time this season when Schaub completed an 11-play, 79-yard drive with a seven-yard pass to Vonta Leach to make it 7-0. The Texans marched downfield again on the next drive and went up 14-0 on a five-yard run by Chris Brown.

Manning was under heavy pressure when he threw an interception to Brian Cushing early in the second quarter. The Texans got to the Indianapolis 12-yard line before Kris Brown's 35-yard field goal pushed the lead to 17-0. Brown also made a 33-yard field goal in the second quarter after the Colts got on the board.

"We've been really, really good and then poor in some situations, so it's my job to find some consistency," Houston coach Gary Kubiak said.

The Colts got on the board when Manning found Pierre Garcon for a 9-yard touchdown about six minutes before halftime. That drive was helped by a 15-yard roughing-the-passer penalty on Antonio Smith for hitting Manning in the facemask..

In the third quarter, the Texans were called for pass interference deep in their own territory, aiding Indianapolis as Manning found Reggie Wayne for a short touchdown pass.

Houston's Jacques Reeves got a 43-yard pass interference penalty on the third play earlier in the drive.

The Colts' first lead came on Manning's touchdown pass to Clark. That drive was helped by a 17-yard pass interference penalty on Houston.

"You can't play a half against this football team," Houston cornerback Dunta Robinson said. "We knew coming out of halftime that this game was far from over."

Manning finished 27 of 35 for 244 yards. Schaub was 31 of 42 for 284 yards with two TDs and two interceptions.

With files from CBCSports.ca