DENVER (AP) -- This one turned out to be more about ''if'' than ''how many'' for Peyton Manning and the Denver Broncos.
Derailed by their own mistakes, to say nothing of an in-your-face Jacksonville Jaguars defense, the Broncos found themselves in quite a tussle through most of a surreal Sunday afternoon.
Not until early in the fourth quarter, when Knowshon Moreno ran for his third touchdown, did the undefeated Broncos have any sense of security against the winless Jags. Denver won 35-19 but fell well short of covering the record 27-point betting line in Las Vegas.
''There was a lot of bad football out there,'' receiver Wes Welker said. ''We've got to correct that stuff and come out better next time.''
Manning went 28 for 42 for 295 yards, marking the first time he's been held under 300 this season. His two touchdown passes gave him 22 on the year, a record for an NFL quarterback through six games.
But he also lost a pair of fumbles on bad exchanges from center and threw his second interception of the season, which linebacker Paul Posluszny returned 59 yards for a touchdown to pull the Jaguars within 14-12 before the half.
At that point, it was clear this would be more than another stat-padding day for Manning and Co. That feeling was reinforced when Chad Henne led the Jaguars on an 80-yard touchdown drive against the banged-up Broncos (6-0) to make it 21-19 after Manning opened the third quarter with a TD drive of his own.
''Sometimes, you score a lot of points and people take it for granted,'' Manning said. ''Even people in your own building can take it for granted. It's not easy to win football games. I learned a long time ago, don't take winning for granted.''
Justin Blackmon had 14 catches for 190 yards for Jacksonville, which fell to 0-6 for the first time, but gave the Broncos a harder time on offense than any team they've faced this season.
In the second quarter, the Jaguars forced Denver's first punt of October. They got in front of receivers' routes, and when a Bronco did catch a pass, Jacksonville defenders wrapped up immediately.
The Jags gave up 407 yards, but very few were cheap. Were it not for a series of odd decisions and untimely mistakes, this one might have been even closer.
It began during Jacksonville's first possession, when tight end Clay Harbor was wide open for a big gain, but Henne underthrew him. Three plays later, coach Gus Bradley called a fake punt the Broncos diagnosed perfectly, leaving them only 27 yards from their first score, a 3-yard pass from Manning to Julius Thomas.
Denver's second touchdown - Manning to Welker for 20 yards - came after the Jaguars stopped Manning on third-and-long but had that nullified by a personal foul on defensive end Andre Branch.
There was a muffed snap on a field goal attempt, Bradley's failed decision to go for 2 after Posluszny's interception return, and a pass interference penalty that helped Denver on its opening drive of the third quarter. In all, Jacksonville did enough silly things to lose despite racking up 362 yards of offense.
''What I saw was a team that played with a lot of emotion and it got the best of us,'' Bradley said. '' I just felt like the emotion got the best of us, but we settled down.''
Only in Denver, where it's Super Bowl or bust this season, would a 16-point win be the cause for so much hand-wringing. But frankly, the lead-up to this game wasn't about who would win but about whether the Broncos would cover the record-setting spread and when Manning would come out of the game.
Henne, whose wife was in labor back in Jacksonville, threw for 303 yards against Denver's league-worst pass defense. The Broncos welcomed back Champ Bailey, who found himself on the island against Blackmon for much of the afternoon.
''This is still the NFL,'' Bailey said. ''Nobody's a cakewalk in this league.''
Despite their struggles, Denver ended up undefeated without linebacker Von Miller, whose six-game suspension officially ends Monday.
But the Broncos also lost right tackle Orlando Franklin to a left knee injury in the third quarter and he hobbled out of the locker room on a cane - adding another question mark as they head to Indianapolis for Manning's return to play his old team.
Among other things, that game is being billed as Denver's toughest test to date. Turns out, the Jaguars gave the Broncos plenty to sweat over, as well.
Notes: DL Malik Jackson had both of Denver's sacks, spread three plays apart in the third quarter. ... Jags receiver Cecil Shorts III left in the first quarter with a right shoulder injury. ... Never a great sign for a defense: Denver CB Chris Harris led the Broncos in tackles with 11.