Quarterback Manning threw a season-high four interceptions - the Bengals' Dre Kirkpatrick returning a 30-yard pick late in the game for a touchdown to seal Cincinnati's place in the play-offs.

Denver's spot in the post-season had already been secured but Manning's performance will have done little to quiet growing criticism of the former Indianapolis Colts star.

Manning broke the NFL record for career touchdown passes in October, but doubts have since emerged over the 38-year-old's arm strength, and he accepted that he was at fault for Monday's defeat.

"Obviously the fourth quarter though, I made some bad throws and that really put us in a bind," Manning said.

"It was a bad throw, the guy had good coverage, had a little route to DT [wide receiver Demaryius Thomas], the guy covered it well.

"I shouldn't have thrown it to him, should have gotten off, probably had Emmanuel [Sanders] open over the middle. I might have even had [tight end] Julius [Thomas], I think his guy might have fallen down. Definitely picked the wrong guy to throw it to.

"It wasn't good - four interceptions. You're not going to beat very many good football teams [like that].

"We did some good things during the third quarter, gave ourselves a chance and had the lead there in the fourth and then field position wasn't very good. We couldn't flip it and then, of course, turning it over there at the end for the interception for the touchdown, that put them up two scores so that's definitely a throw you can't make in that situation."