INDIANAPOLIS -- The Indianapolis Colts spent one quarter trying to figure out Denver's confounding ground game.
Peyton Manning spent the next three confusing the Broncos defense.
Manning led the Colts to six scores on his final eight possessions, rallying Indianapolis from an early 10-point deficit to an impressive 38-20 victory Sunday -- giving the Broncos one more anguishing chapter in this lopsided rivalry.
"They tried to break our will," Colts cornerback Marlin Jackson said, referring to Denver's steady diet of powerful runs.
Instead, the Colts eventually broke the Broncos with some nifty adjustments and surprise reinforcements.
Eight-time Pro Bowl receiver Marvin Harrison left in the second quarter with a bruised left knee and did not return. Outside linebacker Rob Morris was carted off the field just before halftime with a sprained left knee. Former Pro Bowl safety Bob Sanders (ankle) and running back Joseph Addai (shoulder and back) couldn't finish the game, either.
The patient Super Bowl MVP never fretted, even without his most reliable target -- Harrison.
Manning completed 20 of 27 for 193 yards and three touchdowns, and Addai gave the Broncos a dose of their own medicine by carrying 19 times for 136 yards and another score before leaving early in the fourth quarter.
The result: Indianapolis is now undefeated for the third straight September, still has the league's best September record (18-2) since 2002 and extended its league-best win streak to nine games when the playoff wins are included.
Denver (2-2), meanwhile, has now lost two straight and an agonizing five of the last seven in the series since Tony Dungy took over in 2002.
"They don't turn the ball over; they don't make many mistakes," Denver quarterback Jay Cutler said. "You have to play close to perfect against this team. We have to go back and see what our problem is. The way we're going now, doesn't get it."
The Broncos certainly had a chance, though.
They drove for a field goal and a touchdown on their first two series, as Travis Henry repeatedly gashed the Colts run defense. Henry carried 26 times for 131 yards in the game.
By halftime, the Broncos had piled up 160 yards rushing, the NFL's highest single-half total all season, and somehow still found themselves in a 14-13 deficit because they had to settle for two field goals when they needed touchdowns.
"You either get it done or you don't, and we didn't," Broncos coach Mike Shanahan said. "You've got to play error-free football against this team. We had opportunities to score touchdowns on our first two drives and just didn't."
Eventually the Colts took advantage of the situation.
Addai ran 14 yards for the Colts' first score, and Dallas Clark caught a 9-yard TD pass on their next possession to forge the 14-13 halftime lead.
When the second-half opened, Manning seized control.
He used a rare quarterback sneak for a 21-13 lead and converted Jackson's interception into a 3-yard TD pass to Clark in the corner of the end zone. Clark finished with six catches for 76 yards against a Denver defense that had deactivated safety John Lynch and defensive tackle Sam Adams before the game.
"I was outside a lot today, which I wasn't expecting," he said. "I knew we were going to try it, but I think with some of the injuries we wanted to go back to it just to see how it worked."
Jay Cutler, who was 13 of 21 for 131 yards with one touchdown and one interception in the return to his home state, answered with his own 2-yard run to cut the deficit to 28-20.
Manning countered with another long drive, throwing a 5-yard TD pass to Reggie Wayne and setting up Adam Vinatieri for a clinching 22-yard field goal with 2:34 left.
Henry left briefly in the third quarter with a sprained right ankle, and he wasn't the only one feeling sore after letting another game slip away to Manning and the Colts.
"You saw the first half; we could have taken the game," defensive tackle Amon Gordon said. "It's tough. Peyton is at the top of his game, and his passing sets up their running game."
Notes: Denver defensive tackle Marcus Thomas also left the game with a bruised right knee. ... Indianapolis tied a franchise record with its 11th straight home victory. ... Denver kicker Jason Elam scored eight points to pass Jan Stenerud for eighth on the career scoring list. Stenerud finished with 1,699. Elam now has 1,702. ... The last time Cutler played in the RCA Dome, he caught the winning touchdown pass in Indiana's Class 3A state championship on a flea flicker.
Copyright 2007 by The Associated Press. All Rights Reserved.