With four games remaining against teams that have combined for a 16-32 record, Denver now is the heavy favorite for the conference's No. 1 seed in the postseason.
Here's what else we learned in Sunday's game:
- Manning's arm might be the weakest in the NFL, but the quarterback proved Sunday that it's plenty strong enough to burn a defense down the seam with a series of perfect passes to the wide receiver duo of Decker and Demaryius Thomas. Manning did uncork a few ducks. As usual, though, they were on passes when he didn't have his feet set due to pressure on the interior. Just three times has a quarterback thrown for 38-plus touchdowns in his first 12 games of the season. This is the second time Manning has done it.
- As well as running back Knowshon Moreno has played this season, the Broncos will not be able to keep Montee Ball off the field down the stretch. More dynamic than Moreno as a runner, the rookie gave the coaching staff a reason to trust him Sunday. Moreno isn't going away, but Ball is emerging as an added weapon for a team that needs two backs because it often plays with the lead and runs so many plays.
- When the Chiefs raced out to a 9-0 start against weak competition, the question was whether they could score fast enough to keep up in a shootout. They have now lost back-to-back high-scoring games with the defense as the culprit. For the second consecutive week, quarterback Alex Smith played a heck of a ballgame, burning secondaries with his arm and making pass rushers pay with his legs. As a running threat in key situations, Smith has been the equal of Colin Kaepernick, Robert Griffin III and Cam Newton this season. He was hurt by several drops on perfect downfield throws.
- The Chiefs are a different defense now than they were during the first half of the season. They have surrendered 480 yards per contest over their past four games after allowing just 309 yards per game in the first eight. After generating 35 sacks in the first seven weeks of the season, the Chiefs have just two in the last six weeks. They have joined the 1969 Rams and 2009 Saints as the only teams to lose three in a row after starting the season 9-0.