KANSAS CITY — Entering Thursday, the 1-4 Denver Broncos and 4-1 Kansas City Chiefs’ season were going in drastically different directions.

This was not the primetime matchup the NFL had envisioned when they put the AFC West rivals on Thursday Night Football.

However, despite a dismal start for Sean Payton and the Broncos’ offense—as the Chiefs had out-gained Denver 211 yards to 81 yards shortly before halftime—Russell Wilson had an opportunity to go into the half only down one possession to the defending World Champions.

Down 10-0 with 1:01 left in the second quarter, Vance Joseph’s defense forced Andy Reid’s offense to punt for the first time in the game.

At this point, the Chiefs had 12 first downs to the Broncos’ four and had 130 more yards than Denver. But the Broncos had the ball at their own 24-yard line with 47 seconds left and timeouts in their pocket to try and put points on the board before halftime.

Thanks to a 15-yard screen to Samaje Perine and a five-yard completion to Courtland Sutton, the Broncos faced a 3rd-and-5 from their own 44 with 28 seconds remaining and one timeout.

Payton and the offense had plenty of time to still move into field goal range.

However, on third down, Wilson was sacked by Chris Jones and George Karlaftis to set up a 4th-and-12 and an obvious punt situation for the Broncos.

But the clock stopped.

Timeout, Broncos, the officials announced.

Did the officials mean the Chiefs? Nope.

“Listen, that’s a boneheaded mistake by me,” Payton admitted after the game, when asked why he called the timeout instead of letting the clock run out. “[The Chiefs] were calling one as well. I’m off a down. That was stupid.”

Payton thought third down was upcoming, not fourth down.

Playing against most teams in the NFL, that wouldn’t have been costly. But Patrick Mahomes doesn’t need much time to score.

After a 29-yard punt and a five-yard penalty by Riley Moss during the play, Kansas City had the ball on their own 39-yard line with 15 seconds left.

Two plays later and the Chiefs had moved the ball 19 yards in 11 seconds to set up a 60-yard field goal for Harrison Butker, which he drilled to extend Kansas City’s lead to 13-0 at halftime.

What could have, and certainly should have, been at worst a 10-0 deficit heading into halftime turned in to a 13-0 deficit with Denver’s inability to run out the clock, and even worse, call a timeout that benefited Kansas City.

“Look, that’s a three-point swing there,” Payton said, when asked about how big the end-of-half sequence was in the game. “But, man, there’s so many other things that jump in to my mind relative to opportunities missed. But I was encouraged. I thought they played hard. We’ll see this team in two weeks and, you know, that’s kind of what I told them afterwords. You can be disappointed, but don’t get discouraged.”

In the fourth quarter, after the Chiefs took the 19-8 lead, Denver got the ball back with 1:55 left in the game. The Broncos were faced with the near-impossible task of scoring twice to win.

In that moment, the three-point swing at the end of the first half loomed large.

Just two plays later, however, the Broncos’ fumbled and solidified their 11-point loss.