Manning knew the Broncos (7-2) were already missing stars DeMarcus Ware and Aqib Talib and that Emmanuel Sanders was hurting.
So, he gutted it out, telling his coach and athletic trainer he felt fine even though he’s been dealing with a sore right foot, throbbing ribs and aching right shoulder.
"By going out there and trying to help the team," Manning lamented, "I ended up hurting the team."
He finished the day with just 35 yards on 5-of-20 passing, zero touchdowns, four interceptions, two sacks and an almost unheard-of zero passer rating before being benched late in the third quarter in favor of longtime backup Brock Osweiler.
"He’s still a great quarterback — just not what he used to be," Chiefs linebacker Derrick Johnson said.
With his first, modest completion, Manning set another milestone, supplanting Brett Favre for most career passing yards. But the Chiefs (4-5) prevented him from getting the one record he really wanted: most career wins.
They did it on the strength of five interceptions, five field goals and two touchdowns by Charcandrick West, including an 80-yard catch from Alex Smith.
Manning entered the day with 71,836 yards through the air, 2 shy of Favre’s record and tied with Favre with 186 victories.
Asked if he pulled Manning because of injuries or ineffectiveness, Broncos coach Gary Kubiak said, "To be honest with you, I was protecting him because I was worried about him."
Kubiak promptly accepted the blame for the debacle, saying he was kicking himself for even playing Manning in the first place.
Manning, who refused to use injuries as an excuse, didn’t practice until Friday but on Saturday showed up in the trainer’s room with a new ailment — sore ribs.
"And I probably should have right there said, you know, no, he’s not going to go this week," Kubiak said. "But he’s a competitor, he wanted to play."
Kubiak is sticking with Manning — who has just nine TDs and an NFL-high 17 interceptions — as his starter. Asked if he’d start Osweiler at Chicago next week, Kubiak said, "Peyton’s our quarterback. If he’s healthy and ready to go, Peyton’s our quarterback."
That’s a big "if."
"I think I’d like to be able to practice during the week," Manning said. "I didn’t practice until Friday and that’s not ideal for anybody to go out and play, and so I’d like to be healthier to practice some on Wednesday, like I have in the past, and on Thursday."
The only highlight for Manning was a 4-yard pass to running back Ronnie Hillman that gave him the record. Even that didn’t come until he’d thrown his first interception, gotten sacked and fumbled.
With Manning’s sore right foot preventing him from stepping into his passes properly and getting zip on his throws, Kubiak finally turned to Osweiler with Denver down 22-0.
The Broncos saw their nine-game AFC West winning streak come to an end with their first loss to the Chiefs since Tim Tebow was their quarterback in 2011.
The Chiefs won their third straight game thanks to a stifling defense and Cairo’s field goals of 48, 49, 34, 33 and 50 yards.
Safety T.J. Ward was ejected for punching wide receiver Jeremy Maclin, who took out Ward on West’s 80-yard TD catch-and-run that followed Eric Berry’s interception of Osweiler’s pass in the end zone.
"I got emotional. I didn’t really mean to punch," Ward said, adding he’s concerned he’ll follow Talib on the NFL’s suspended list for losing his cool.
The game was halted after Manning’s milestone throw, and Joe Horrigan from the Pro Football Hall of Fame secured the ball.
"I think that’s an awkward situation to have any type of stoppage of play, in the middle of a game," Manning said. "I wasn’t off to the best start."
Manning surely wanted no mementoes from this game.
Note: Sanders passed concussion protocol, but was held out after getting hurt in the second half. … The Broncos haven’t been shut out since the Raiders held them scoreless on Nov. 22, 1992. … Osweiler finished 14 of 24 for 146 yards, a TD and an interception.