KANSAS CITY - Everyone thought it was going to be a shootout. No one thought it was going to a blowout when these two division leaders convened a Sunday night summit at Arrowhead Stadium. But the Chiefs did exactly that in a 45-10 victory.

The Chiefs put up 551 yards of offense, the most allowed by the Bengals since Drew Brees and the Saints racked up 595 in a 2006 Bengals' victory and 554 in a 2007 loss to Cleveland for the third most yards allowed under Marvin Lewis.

Thanks to Justin Tucker's first missed point after attempt of his career in Baltimore, the 4-3 Bengals are percentage points out of first place behind the 3-2-1 Steelers.

While the Bengals defense got overwhelmed by a numbing number of missed tackles and coverage errors, Chiefs quarterback Patrick Mahomes carved them for 320 yards in a brisk three quarters and they lost WILL linebacker Vontaze Burfict to a left hip injury. Mahomes finished a seamless 28 of 39 for 358 yards and four touchdowns and K.C. could have had more but the Bengals stopped them on a fourth down at the Cincinnati 5 with 4:14 left in the game.

It didn't get any better in the fourth quarter, when left end Carlos Dunlap and safety Shawn Williams were called for 15-yard penalties, Dunlap for bumping an offensive lineman after he pushed Mahomes out of bounds and Williams for spearing the ball carrier when he was down.

Mahomes could do no wrong even when he did. He dropped the shot-gun snap, headed right, went back left and found wide receiver Tyreek Hill all alone at the front pylon for a three-yard touchdown. That made it 45-10 for the most points scored against the Bengals in the eight seasons of the Green-Dalton Era and the most they've allowed since a 49-31 loss to the Bills in 2010.

When it rains it pours. That fourth quarter saw Bengals wide receiver John Ross re-aggravate his groin injury in his first game back and left without a catch. Mason Schreck, part of a crippled tight ends group, got carted off with what is feared to be a season-ending knee injury.

Quarterback Andy Dalton finished a disappointing night for the offense on 15 of 29 passing for just 148 yards and a 63.6 passer rating. Wide receiver A.J. Green managed his second 100-yard game of the season with 117 on seven catches and tight end C.J. Uzomah scored their only touchdown, but no one other than Green caught 30 yards as wide receiver Tyler Boyd was held to three catches for just 27 yards.

After Mahomes' 50-yard bomb to wide receiver Sammy Watkins on the first snap of the second half set up the touchdown that made it 31-7, Dalton went zone read and tried to hit Green on a back-side slant. But safety Ron Parker undercut the route and ran it 33 yards for pick six to make it 38-7 on 14 points in nine seconds and there was still 11:10 left in the third quarter.

The Bengals offense committed the cardinal sin playing the high-flying offense of head coach Andy Reid's Chiefs and punted three times against the NFL's worst ranked defense as Kansas City built a 24-7 half-time lead.

And when one of those punts imploded for a fumble and another one sailed for a touchback with 1:13 left in the half, the Bengals defense couldn't stand up in a disheveled display that featured enough missed tackles of an entire season when Kansas City rolled to a staggering 319 yards in the first 30 minutes.

Mahomes, the gun-slinging second-year player, began the night two touchdown passes away from Andrew Luck's NFL-leading 20 and he regained the lead with 1:55 left in the half on his third touchdown pass of the night to wide open tight end Demetrius Harris to give KC a 21-7 lead It was a shockingly easy 17-yard play that summed up the night. Nobody touched Harris off the line as he got behind cornerback Dre Kirkpatrick and got wide open in the middle of Kirkpatrick, dropping defensive lineman Sam Hubbard and Williams.

But as badly the defense played, the inability of the offense to take control of the game against a Chiefs defense on pace to allow the most yards in NFL history was the most disturbing aspect of the half.

On the ensuing kickoff the Bengals got the ball at their 40 when the kick slithered out of bounds. But they couldn't run it against a defensive giving up 5.4 yards per carry and when Green ended his monster 110-yard half with drop, another incompletion forced a punt and Mahomes' next four passes each got easy first downs on the way to a chip-shot field goal with eight seconds left in the half that made it 24-7.

So twice the Chiefs hit the Bengals in their Achilles' Heel. Now they've allowed points in the last two minutes of the first half in 17 of the last 24 games.

Mahomes cruised to first half 19 of 25 passing for 234 yards and a wow 144 passer rating. While Mahomes hit three receivers for at least 47 yards, all but eight of Bengals quarterback Andy Dalton's yards went to Green. Green had six of the ten completions as Dalton went 10 of 19 and his TD pass going four yards to tight end C.J. Uzomah on third down to cut it to 14-7 with 7:25 left in the half.

That was a heck of a drive because they had to overcome holding calls on both guards (Clint Boling and Alex Redmond) and Green accounted for 77 of the 82 yards.

But the Bengals had no answers in all three phases. While Bengals running back Joe Mixon had 23 yards on nine carries, Mahomes took off three times for 42 yards.

The Chiefs went 95 yards on their first possession (when old friend Josh Shaw was called for a hold on the opening kickoff) and Kansas City's longest drive of the season was as bad as it sounds.

Missed tackles by safeties Jessie Bates and Shawn Williams began the drive on wide receiver Tyreek Hill's shimmying 27-yard catch and run. Cornerback William Jackson missed wide receiver Demarcus Robinson at the sticks for a first down and on third-and-two Mahomes fooled them badly when he kept the ball on a zone read and no one was near him on the right perimeter. Somewhere in there right end Michael Johnson had running back Kareem Hunt stopped for no gain, but he went too high and Hunt went low for six yards on his way to seven yards a shot in the first half.

Then Hunt really hit them in the gut. Kirkpatrick and a swarm looked like they had him for a two-yard loss, but Hunt emerged from the mess and then leaped over the 6-2 Bates to finish off a 21-yard run that won't be used in any defensive textbooks.

Mahomes then got an easy six-yard touchdown pass when he sprinted to the right edge in a two-way go, caught linebacker Hardy Nickerson in no man's land and flipped it over him to Hunt to give the Chiefs a 7-0 lead in the middle of the first quarter.

The Chiefs' second drive was more of the same for the defense. Missed tackles and looking about 10 miles per hour slower. Both happened on tight end Travis Kelce's 43-yard ramble down the left sideline. Slot cornerback Tony McRae missed the tackle on the edge and Bates, Williams and the linebackers couldn't get him.

But the drive was saved when Bengals head coach Marvin Lewis successfully challenged a completion into the red zone and the Chiefs were forced to try a 53-yard field goal. Harrison Butker cooperated with his first miss of the year when he hooked it.

It was at that point the Bengals had to take advantage and get back into the game. They had great field position at their own 43, but they did just the opposite and imploded.

Their tackles blew up the series. Right tackle Bobby Hart was called for a false start and then left tackle Cordy Glenn allowed pressure and Dalton's scramble couldn't get a desperation completion to Mixon.

Then the punt was a disaster. They appeared to try to run a fake, but personal punt protector Clayton Fejedelem dropped it and the Chiefs recovered at the Bengals 32.

The Chiefs didn't blink going up 14-0 with 13:18 left in the first half when they promptly parlayed two missed tackles by linebacker Vontaze Burfict into Hill's 16-yard completion (he caught it over the middle, avoided Burfict and then raced across the field out of bounds without being touched) and Hunt's 15-yard touchdown catch. Mahomes had pressure bearing down from his left and chucked it off his back foot to Hunt in a hurry and Burfict, wearing the defense's helmet microphone helmet, couldn't wrap him up.

The Bengals couldn't take advantage of scoring first to open the game. Mixon rolled for five yards on the first snap, but Green appeared to get mauled by cornerback Orlando Scandrick on a second-down incompletion and on third down Mixon couldn't get anywhere on a flip into the flat because two defenders were all over him.