The Broncos' high-powered offense struggled throughout the night, as they went numerous three-and-outs without converting a first down during the second and third quarters.
The Broncos will enter Week 8 versus the Washington Redskins at 6-1 and in second place in the AFC West.
The loss to the Colts revealed that the Broncos offense can be slowed down, and that the Broncos as a team aren't as invincible as many people thought.
What are a few takeaways from the Broncos' first loss of the season?
You could say in response to this slide title, "Yeah, no kidding," but coming into this game, the Broncos offense was as unstoppable as it got.
Through six games, Denver's offense had scored 265 points—an NFL record—and had averaged 44.2 points per game.
Although it put up 33 points versus the Indianapolis Colts in Week 7, the offense slowed down—and it slowed down big time.
The Broncos offense went seven consecutive three-and-out drives without a first down between the second and third quarters. During that drought, the Colts scored three touchdowns to take control of the game.
Through bump-and-run coverage, and repeatedly pressuring and hitting Manning, the Colts defense rattled the Broncos offense.
That's the reason why Denver suffered its first loss to Indianapolis.
Did you know that Demaryius Thomas was active for Sunday night's game?
If you didn't know, nobody would blame you.
If you look at Thomas' final stat line, it doesn't look that bad—four receptions for 82 yards and a touchdown.
That is until you watch the game tape and see that he was absolutely shut down by Colts cornerback Vontae Davis. Thomas didn't have an impact in the game until early on in the fourth quarter when he caught a touchdown to cut the deficit to 13 points.
There were a couple of occasions where Manning underthrew Thomas, but in general, the Broncos' receiver was a no-show for the Broncos' toughest game of the year.
When it looked as if the Denver Broncos were going to come back to win the game on their 83-yard drive which brought them to the Colts 2-yard line, Ronnie Hillman had been the Broncos' running back on the field for that entire drive.
On 1st-and-goal from the 2-yard line with the Broncos down 39-30 with 3:15 remaining, Manning gave Hillman his first carry of the drive.
It would end up being a move that ended up costing the Broncos the game.
Hillman—who has been known for his tendency to fumble the football—fumbled the football upon being hit, where it would end up being recovered by the Colts' Antoine Bethea.
Knowshon Moreno has established himself as the Broncos' go-to running back, as Hillman and Montee Ball have seen their snaps and touches diminish over recent weeks.
Hillman's costly fumble versus the Colts won't improve Denver's confidence in the second-year runner.
Despite his early season struggles with dropped passes, Decker has re-established himself as Manning's go-to guy in 2013.
The fourth-year receiver caught eight passes for 150 yards—a career high—and one touchdown in the 39-33 loss.
Decker led the Broncos in touchdown catches in 2012 with 13.
Through seven games in 2013, he leads the Broncos in receiving yards with 627.
Despite the Broncos' other receivers being shut down for the majority of the game, the University of Minnesota product was the one consistent threat Manning could depend on.
Luck had one of the best games of his young career in the Colts' 39-33 victory over the Broncos.
Luck completed 21 of 38 passes for 228 yards and three touchdowns with zero turnovers.
On the other hand, Manning did have a productive night, but he turned the ball over twice—both turnovers which led to a combined 12 points on the Colts' end.
The Colts' second-year quarterback bested the veteran Manning, and had a Manning-like performance by efficiently moving his offense down the field, controlling the time of possession and succeeding in not turning the ball over.
Luck's excellent performance—combined with Manning's struggles—led to the Colts giving Denver its first loss of the season.
You could say the same about every quarterback in the NFL, but one ingredient for slowing down Manning has been this—hit him, and hit him often.
For the first six weeks of the NFL season, despite the loss of Ryan Clady to season-ending injury, Manning hadn't been hit often. In fact, Manning was the least sacked quarterback in the NFL, as the Broncos allowed just five sacks on the season. That is four less sacks allowed than the second-best team in the NFL, the Chicago Bears.
It is no wonder why it looked as if the Broncos offense was playing flag football during the 6-0 start.
Sunday's game versus the Indianapolis Colts was a rude awakening.
The Colts consistently pressured Manning, whether that was through the interior during Pat Angerer's interception in the fourth quarter, or whether that was off of the edge from the NFL's leading sack specialist, Robert Mathis.
Indianapolis came up with the perfect game plan to rattle the four-time NFL MVP.
And it worked to perfection.
Von Miller added 15 pounds of muscle during his six-game suspension to beef up his playing weight to 270 pounds.
He claims he's as fast as he's ever been despite the added weight.
In his first start since serving his six-game suspension, Miller was mostly a non-factor—he had two tackles and looked solid in run support in helping Denver stop Trent Richardson on a few short-yardage conversions in the first half.
But for the most part, he was unable to pressure Colts quarterback Andrew Luck, or provide any momentum-changing plays.
When the Washington Redskins visit Mile High to face the Broncos in Week 8, we'll have a better idea of whether Miller's weight gain will pay dividends for the Broncos.
The Denver Broncos' regular-season winning streak finally comes to a close in Week 7 of the 2013 season.
Since the Broncos came back from a 24-point deficit to defeat the San Diego Chargers in Week 6 of the 2012 NFL season, Denver had not lost a regular-season game—before the loss to the Colts, the Broncos had run off 17 straight victories in the regular season, fourth best in NFL history.
Although Week 7's 39-33 loss to the Colts was painful, it's a blessing in disguise.
After the Broncos' 6-0 start behind the superb play of Manning and the offense, pundits were already talking about the Broncos going undefeated in the regular season.
This is a team that entered the postseason last year on an 11-game winning streak as favorites to play in the Super Bowl—only to lose its first postseason game to the eventual Super Bowl-champion Baltimore Ravens in the divisional round.
This year, the Broncos have already suffered a painful loss to the likes of the Colts in Week 7. The Colts revealed weaknesses in the Broncos' armor and a blueprint on how to slow down Denver's offensive attack.
Luckily for the Broncos, unlike their loss to the Ravens in last year's playoffs, they'll have 10 more weeks to cure their woes.
A humbling loss couldn't have come at a better time for the Broncos.