DENVER — The stage seemed too big, the primetime lights too bright for a Broncos franchise that is shockingly residing among the NFL cellar dwellers for going on three years.

They haven't been to the playoffs for going on four years. They were 5-11 and 6-10 the two previous seasons and 2-4 this year.

Come again why Rocky Mountain region thought the Broncos were going to at least give the Kansas City Chiefs a game if not beat them? 

Even against a Chiefs team that lost its superstar quarterback Patrick Mahomes II early in the game to a knee injury, the Broncos were ridiculously overmatched while getting drubbed, 30-6 to a Kansas City team that was beat up before the game, and severely injured afterwards.

"It hurts,'' said Broncos right guard Ron Leary. "Primetime, you want to put on a better performance than that. It's how the league works sometimes. It didn't go our way tonight. We got a lot of games left. We'll take a couple days off and then go back to work. You still have to play the game so you've got to keep working."

It was an AFC West rivalry game in which both teams suffered major setbacks.

The Broncos' offense was pathetic after its opening drive. The offensive line couldn’t protect quarterback Joe Flacco, who couldn’t hold on to the ball on his way down and became increasingly uncomfortable in the pocket.

"All levels of our passing game was the problem,'' said Broncos head coach Vic Fangio. "Protection sometimes. Receivers not getting open sometimes. Then some good coverages that maybe we weren't ready for. It certainly a probelm we have to get rectified moving forward."

Denver’s punt team was as bad as its pass protection and the Kansas City Chiefs crushed the Broncos, 30-6 on a comfortable warm mid-October Thursday evening before 74,121 disappointed fans at Empower Field at Mile High.

The Broncos fell to 2-5 and last place in the AFC West while the Chiefs moved their AFC West first-place record to 5-2. The Chiefs have won eight in a row against the Broncos.

The Chiefs, though, may have suffered a far more devastating loss as Mahomes suffered a serious right knee injury in the second quarter.

“You feel for anybody who has something that looks like it may be pretty serious,'' Flacco said. "That’s not just other quarterbacks, that’s everybody. A young guy like that who’s starting off the career like he has and starting off this season the way he has, it’s not easy to watch guys go down with injuries like that.''

There were Twitter reports from doctors that said Mahomes appeared to have suffered a dislocated knee cap. Which, if it was popped back in while he was on the field, explains why he was able to walk off the field under his power. Mahomes was also immediately ruled out.

"I didn't want to see Mahomes hurt, not at all,'' said Broncos cornerback Chris Harris Jr., who was standing over the injured Mahomes calling for medical help.

Veteran backup Matt Moore came off the bench with the Chiefs up two touchdowns and hit Tyreek Hill on a 57-yard pass in the third quarter that gave Kansas City a three-touchdown cushion.

Given the hype of this game and the Broncos hopes of showing they are a playoff-caliber team again, Denver laid a rotten pigskin.

It started well as the Broncos went 75 yards on their opening drive for a touchdown. Kansas City appeared to have the Broncos stopped twice on third downs, but each time a defensive penalty gave Denver a fresh set of downs.

Flacco was 4 of 4 for 47 yards on the opening drive, which ended with Royce Freeman ramming in for a 1-yard touchdown.

When the Chiefs jumped offside on the extra point, Broncos coach Vic Fangio elected to go for the 2-point try from the 1 yard line, but Phillip Lindsay was stopped short. It was 6-0 Broncos, not 7-0.

The Chiefs then scored the next 30 points. Mahomes answered with his own impressive drive, going 5 of 5 for 47 yards with the final 21 yards going to Mecole Hardman for a touchdown. Hardman snuck by defensive back Will Parks, who later left the game with a hand injury, and safety Kareem Jackson for the touchdown.

From there Flacco’s protection broke down as he struggled to find open receivers, particularly on third downs. He was sacked deep in Broncos territory on third down of his next drive, and Coby Wadman’s punt was returned by Hardman for 36 yards to the Denver 21.

The Denver defense did well holding the Chiefs to a Harrison Butker field goal that put Kansas City up, 10-6.

Another sack of Flacco killed the Broncos’ next drive but then instead of punting it way, a fake was called. Wadman sprinted left but had no receiver open -- with the fake on, a receiver missed the call and didn't get out in the route -- and had it to eat it for a sack at his own 38. So make that 9 sacks for the Chiefs.

Mahomes moved the Chiefs deeper in the Broncos’ territory but on fourth and 1 from the 5 yard line, his quarterback sneak picked up the first down – but also left him clutching his right knee in obvious pain.

“Not too many people get hurt on sneaks,'' said Chiefs coach Andy Reid, when asked if he regretted calling that play for Mahomes. "It was a freak thing, sometimes it happens. I was really proud of how our guys stepped up and didn’t let themselves down. You’ve seen that over the years where teams let themselves down when one of your best players get hurt, particularly the quarterback. But I was proud of how our guys stepped up and just kept battling. I thought they really upped their game.”

Moore, a bit tentative initially, couldn’t lead the Chiefs through those final 3 yards so Butker kicked another field goal for a 13-7 lead.

On the Broncos’ next possession, Flacco was sacked by blitzing linebacker Anthony Hitchens and fumbled the ball back to his own 5-yard line, where Chiefs linebacker Reggie Ragland picked it up and walked into the end zone for a defensive touchdown.

The Broncos had a chance to add more points after Mahomes left but Brandon McManus missed right on a 45-yard field goal attempt.

Flacco was 21 of 34 for 213 yards but his 8 sacks accounted for 72 yards in losses and he fumbled twice, with one resulting in a Kansas City touchdown. He and the Broncos were also a horrific 1 of 13 on third downs. They were 2 of 14 on third down four days ago against Tennessee.

Make no mistake, first-year offensive Rich Scangarello has hit his first bout of adversity as he struggles to come up with a successful third-down play call.

“We’re just not playing good football,'' Flacco said when asked to explains the offense's dysfunction on third down. "They came after us and we kind of let them come after us. You’ve got to give a lot of credit to them. They played really physical. They came hard. They played downhill and we were in a lot of bad situations.”

Courtland Sutton has six catches for 87 yards as he continues to establish himself as the Broncos' new No. 1 receiver. Emmanuel Sanders has five catches for 60 yards.

The Broncos have not been able to run the ball as Lindsay and Freeman combined have just 71 yards rushing on 21 carries, a 3.4-yard average.

Mahomes, the league's defending MVP, was 10 of 11 for 76 yards and a touchdown before his injury.

"I was devastated for him, obviously,'' said Moore, who completed 10 of 19 for 117 yards and the TD to Hill. "He's been down and popped up pretty quick. This one, obviously, wasn't that case. So I just hope he's okay. At the same time, we have to go and win a football game, and so I've been in this position before and you just kind of have to move forward and go, just wishing the best for your buddy."

BRONCO BITS

The only surprise on the Broncos’ game-day inactive list was inside linebacker Corey Nelson, who had played in first six games.

The Broncos had hoped right tackle Ja’Wuan James could dress if in a swing tackle role, but it was determined his sprained left knee needed at least one more week. James has missed the past six games. …

Broncos three game captains Thursday were running back Royce Freeman, defensive end Shelby Harris and special teamer Trey Marshall.

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