DENVER -- The Broncos believe time ran out on the Kansas City Chiefs on a pivotal play in Kansas City's game-winning drive Monday night.

"It definitely was at zero. The replay showed that," Broncos linebacker Brandon Marshall said. "The ref told us that the ref that was supposed to be watching it just missed it. ... He told us that. The ref told us the guy that was supposed to be watching the clock just missed it.

"So maybe he got caught up in watching the game because it was a good game, but you've got to do your job. Come on, that was huge. That was big."

The Chiefs overcame a 10-point Broncos lead in the fourth quarter with back-to-back touchdown drives in the final 12 minutes, 46 seconds in a 27-23 victory. Kansas City scored the game-winning touchdown on a 4-yard run by Kareem Hunt with 1:43 to play.

However, four plays before the scoring run, the Broncos say the play clock ran out on the Chiefs on what was a 35-yard completion from Patrick Mahomes to tight end Demetrius Harris on a third-and-7. The play moved the ball from the Broncos' 46-yard line to the 11-yard line just before the two-minute warning.

Replays, including those shown on the stadium's video boards, seemed to show the play clock was at zero before the ball had been snapped.

"My opinion, the clock was on zero,'' Broncos coach Vance Joseph said. "But that's not my job. ... And he said he looked up and it was zero and the ball was gone. I disagree. I disagree.''