The Broncos got one of the best wins by any team this season, coming back from an 11-point fourth-quarter deficit to beat the Chiefs 28-24. Denver got massive, heroic efforts from its offense and its defense, especially in the fourth quarter.

Sean Payton and the Broncos moved to the top of the AFC West at 6-2 and erased the head-to-head advantage the Chiefs had entering the game. The Broncos have won four straight games, surviving a brutal opening stretch; they have already faced the Chiefs (twice), the Jaguars, the Rams, the 49ers and the Seahawks. A winning record would have been a success, but 6-2 is a resounding one.

It's not just a big result for the division and potential playoff implications, but for what is says about both teams. Games like these -- postseason-caliber matchups -- teach us a lot about where both clubs are and where they could be headed. These are the five lessons we learned.

1. Bo Nix's fourth-quarter magic is inexplicable ... and incredible

One didn't need to watch the first three quarters to comprehend how Bo Nix was playing. The boos on the broadcast told the story. Such is life for a quarterback: goat in the eyes of fans one minute, GOAT the next.

Entering the fourth quarter, Nix was 15-for-26 for 153 yards. Just seven of his 26 attempts had gone for first downs, including just one of eight on third down. It was ugly, and it looked like what Nix had put on display much of the year: very conservative, with little downfield. The boo birds were especially prominent when consecutive drives ended with punts after Nix completed short of the sticks on third down.

And then the fourth quarter came. Nix went 5-for-6 for 84 yards. Was it anything magical? No. But Nix took advantage of a pair of coverage busts in crucial moments. First, this touchdown to Nate Adkins:

Then this quick pass to Jonah Coleman:

Since entering the NFL in 2024, Nix has ...

• 15 game-winning drives, most ever in a quarterback's first three seasons
• 12 fourth-quarter comebacks, tied with Derek Carr for most ever in a quarterback's first three seasons

The Broncos have averaged 8.1 points per fourth quarter under Nix, the highest rate for any starting quarterback since at least 1950.

CBS' broadcast team of Jim Nantz and J.J. Watt explained that when they met with Nix, he couldn't explain his late-game exploits, but it's certainly better to start slow and finish strong than to start strong and finish slow. That much is true.

2. The Broncos' run defense has improved significantly

Of course, Nix owes the fact that he even has a chance in the games he starts slow to his defense being excellent. And it very much was Sunday. The last-second goal-line stand is what will get the most plaudits, but Denver's stout defense throughout the game was crucial.

That starts with stopping the run. In Week 1, Kenneth Walker III ran for 173 yards in a 31-10 Chiefs win. There were missed tackles all over the place -- 24 in total -- and just way too many wide-open holes. Walker had 7.8 yards per carry after contact in Week 1. In Week 8? There were still 16 missed tackles, but Walker had just 2.1 yards per carry after contact. He finished with just 69 yards total.

This has been a season-long improvement for Denver.

3. Andy Reid's late-game management remains suspect

For an offensive-minded head coach with one of the greatest quarterbacks of all time, Andy Reid has had some extremely conservative moments as a coach. Sunday, he had another one. Up three with under three minutes left, Mahomes took a bad, bad sack. It wasn't a great play call, but we can't blame Reid for Mahomes taking a rare awful sack.

We can blame Reid for kicking on fourth and 8 from the Denver 36-yard line. Harrison Butker missed (very) wide right. He is now 2 for 7 from 50+ yards this year.

The execution of the play obviously wasn't what Reid had hoped for, but his thought process there is extremely poor. As I wrote in our weekly overreactions and reality checks:

1. Up three, a field goal helps, but not that much. In fact, if it had gone in, it would have given the Broncos an extra down on their ensuing drive, since they would have needed a touchdown. Going up six is not a good idea in this scenario.
2. Thus, this should have been four-down territory. Could Reid have tried a run on third down? Again, we can't blame him for Mahomes taking a bad sack, but we can blame him for a poor approach.
3. Butker has proved to be unreliable, over and over, this season. This isn't prime Butker. And making matters worse, this was a kick in the rain. When he missed, the Broncos were down just three and had great field position.

Mahomes is actually better at converting fourth-and-8 to fourth-and-12 in his career (3 for 6 -- 50%) than Butker is at kicking from 50+ this year. So yes, even though fourth-and-8 looks bad, it might not have been. And Mahomes had been rolling all game. Speaking of ...

4. Patrick Mahomes got the passing game back on track, but he needs help

The Chiefs' collapse will overshadow an otherwise outstanding game from Mahomes. He was 30 for 41 for 321 yards, three touchdowns and zero interceptions. He took just two sacks against a fearsome pass rush and made several terrific plays while under pressure. His 0.16 EPA per dropback was his best mark since Week 3 and, considering the opponent, it might have been his best game of the year.

On third downs, Mahomes was 6 for 10 for 113 yards and a touchdown. Four of his six completions went for first downs, including conversions of third-and-10 and third-and-12.

But the Chiefs must upgrade their receiving corps. The Chiefs' leading receiver was running back Emmett Johnson (more on him in a bit) with five catches for 128 yards. Tight end Travis Kelce had five catches for 67 yards. Wide receiver Rashee Rice had seven catches but for just 53 yards, and he is very much a quick-pass and YAC guy.

Ever since Tyquan Thornton's injury, Kansas City's deep passing game has evaporated. He has not had a single completion on a throw 20+ yards downfield in any of the past three games, since Thornton's injury. That's tied for the longest streak of his career. (He had seven in the three weeks before that, for comparison's sake.)

Whether it's a big name (George Pickens, perhaps?) or a smaller one, Kansas City must add some downfield firepower. Rice doesn't provide it. Xavier Worthy, for all his speed, doesn't provide it. The rest of the guys are young late-round picks or former UDFAs. More downfield pop would help the run game, too.

5. Young running backs shine

Both the Broncos and the Chiefs added mid-round running backs in this year's draft. Both were expected to play complementary roles: The Broncos already had J.K. Dobbins and RJ Harvey, and the Chiefs already had Walker.

But it's clear that Jonah Coleman and Emmett Johnson deserve more love than the "complementary piece" title suggests. Coleman, in fact, led the Broncos in carries (11), rushing yards (41) and receiving yards (63). He also scored the game-winning touchdown. With Harvey out, he looks like a lead back.

Johnson, meanwhile, also found the end zone. In addition to his 128 receiving yards, he had a 15-yard carry and a 44-yard kick return. He looked like Walker was making would-be tacklers miss on a consistent basis. This was an excellent play design, and look at how Johnson finishes it.

The Chiefs can't run Walker into the ground. Expect Johnson to continue to see significant action.