1. Cairo Santos has a day to remember
While the Chiefs offense couldn't seem to get out of its own way as it got closer to the end zone in the first half, kicker Cairo Santos did his part.
Santos was good from 22, 40, 51 and 34 yards in the first 30 minutes of the game.
Santos hit 7 field goals on the day, which tied him for second-most all-time in NFL history.
It is a Chiefs franchise record, although subdued because it came in a loss.
2. Alex Smith and Jeremy Maclin continue to find rhythm
The Chiefs got on the board with their opening drive thanks to a 15-yard hookup between Jeremy Maclin and Alex Smith on third-and-8. It set up Santos' first field goal of the day.
Improving third-down efficiency was something that was discussed all week, and that field goal on their opening drive because of that third-down conversion became the first points they put on the board on an opening drive all season.
On that particular third-down play, Smith was able to step up and around the pressure and find Maclin up the right sideline for 15 yards.
Later in the quarter when the offense needed a big play, Smith hit Maclin on the quick slant off a play fake and Maclin was off to the races for 44 yards.
It was the kind of chunk play the offense has been looking for.
Smith finished the first quarter 7 of 8 for 132 yards and Maclin had 3 receptions for 67 yards. Maclin finished the game with 11 receptions for 148 yards.
3. Chunk plays by the Bengals offense help get them on the board early
On the first two offensive drives for the Cincinnati Bengals, chunk plays on long receptions from the slot position were the reason they were able to move the ball down the field so quickly.
On their first drive, receiver A.J. Green, who came into the game as the NFL's No. 4 receiver through three games, caught a 36-yard reception on third-and-2 as he lined up over Chiefs defensive back Ron Parker in the slot to the left.
Parker moved down from his normal safety position to help cover the slot now with cornerback Phillip Gaines out for the season with a torn ACL.
Green was able to get behind Parker and despite a bad snap and bobble from quarterback Andy Dalton, he was still able to chuck it up to his No. 1 receiver, who made a great play.
On the second drive, running back Rex Burkhead was lined up in that same left slot position, but this time linebacker Tamba Hali was in coverage.
After Dalton escaped out of the pocket to the left, Burkhead had gotten behind Hali and Dalton found him up the right sideline. The play resulted in a 27-yard gain and set up the second Bengals touchdown of the game, an 8-yard run by Giovani Bernard.
Chunk plays were normal for the Bengals in this game as they averaged 8.9 yards per play.
4. Promising offensive drives by the Chiefs stalled because of negative plays
Whether it was a sack, penalty or a negative play, the Chiefs offense just couldn't get out of its own way when it approached the red zone, where it finished 0 for 3 on the day.
Midway through the second quarter, a 20-yard reception by Maclin was upheld after the Bengals challenged the ruling. In addition, 15 yards were added to the gain due to an unnecessary roughness penalty by the Bengals. The Chiefs offense had found a rhythm and got some help as well.
On second-and-10 from the 46-yard line, Jamaal Charles rushed for 13 yards and displayed some of his impressive footwork to get the Chiefs into Bengals territory at the 33-yard line. On the very next play on first-and-10, the Bengals sacked Smith for a loss of 9 yards.
They couldn't get out of their own way.
On the next drive, the Chiefs would once again move the ball and get into the red zone on the back of Charles' two rushes for 32 yards, but on first-and-10 from the Bengals 20-yard line, they were called for offensive pass interference and then faced a first-and-20.
Two plays later, they called a timeout to think about a third-and-7 from the 23-yard line, but were then called for a delay of game coming out of the timeout.
It was a frustrating end to the first half as Santos' 34-yard field goal brought the score closer, 14-12 going into halftime.
It was another missed opportunity.
De'Anthony Thomas' 68-yard return to begin the second half was called back because of a penalty.
On the Chiefs second drive of the second half, Smith tossed a beautiful go route to Maclin down the left sideline for 33 yards on the first play.
They'd move into Bengals territory and then on first-and-10 from the 20-yard line, Thomas took the end-around for a loss of 8 yards, setting up second-and-18 from the 28-yard line.
Photos from the Chiefs week four matchup against the Bengals
5. Zach Fulton started in place of Laurent Duvernay-Tardif at right guard
After Laurent Duvernay-Tardif started the first three games of the season at right guard for the Chiefs, second-year player Zach Fulton got the nod in his place on Sunday.
Fulton started all 16 games at right guard for the Chiefs last season.
Coming into the game, the Chiefs offensive line had surrendered a league-high 14 sacks on the season.
On Sunday, they allowed 5 sacks and 9 quarterback hits.
6. Starting inside linebacker Josh Mauga left the game early with injury
Just 2:53 into the game, starting inside linebacker Josh Mauga left with a thigh injury.
Mauga was replaced by the rookie fourth-round pick from Georgia, Ramik Wilson.
Wilson finished the game tied for the team lead with 8 tackles on the day.
7. Jamaal Charles has big first half for Chiefs offense
He's the Chiefs best offensive player and Charles once again showed that in the first half against the Bengals as he finished with 113 total yards.
Charles finished with 7 carries for 56 yards and 5 receptions for 57 yards.
Maybe the thing that was even more impressive was the way in which he fought his way through the first and second levels of the Bengals defense, high-stepping his way through the traffic to help put the Chiefs in position to score points.
While the offense couldn't punch it through when they closed in on the red zone, Charles did his part in getting them down there.
The Chiefs scored on all four of their first-half possessions, but unfortunately they were all field goals.
8. Brandon Tate's 55-yard touchdown reception grabbed momentum back for Bengals
After committing several penalties and putting themselves in tough situations, Andy Dalton was able to lead the Bengals down the field on a huge touchdown drive when they really needed it.
On second-and-20 from their own 13-yard line, Dalton found tight end Tyler Eifert on the seam route for 23 yards and got the Bengals out from deep in their own territory. It also got them past a couple of holding penalties on offensive lineman Kevin Zeitler.
The Bengals were able to overcome their mistakes as that drive was soon capped off by a 55-yard strike from Dalton to Brandon Tate, who made a beautiful diving catch down the field on third down.
The Tate touchdown extended the Bengals lead to 21-12 midway through the third quarter.
9. Travis Kelce's fumble late in third quarter setup Bengals fourth touchdown
Late in the third quarter and with the Chiefs trailing 21-15, Travis Kelce fumbled the ball just inches before he was down on the third-down reception and the Bengals returned it to the Chiefs 5-yard line.
The play was reviewed and the officials upheld the ruling.
The turnover gave the Chiefs defense an opportunity to pick up their offense, and they weren't able to do it.
Just two plays after the turnover, Bengals running back Jeremy Hill ran it in for his second touchdown of the game and extended the Bengals lead to 29-15 with just seconds remaining in the third quarter.
Coming into the game, the Chiefs defense allowed touchdowns 75 percent of the time an opposing offense got inside the red zone, which ranked 28th in the NFL.
Last season, the Chiefs led the NFL in red zone defense, allowing touchdowns just 38 percent of the time.
On Sunday, the Bengals were 4 for 4 inside the red zone, while the Chiefs were 0 for 3.
10. Alex Smith once again under pressure
Coming into the game, the Chiefs knew the talent the Bengals had in the front seven of their defense, and despite a change at right guard by the Chiefs, Fulton for Duvernay-Tardif, they still couldn't help keep Alex Smith off the ground.
The Bengals finished with 5 sacks, 8 tackles for loss and 9 quarterback hits.
On the other side, the Bengals did a nice job of protecting Dalton throughout the game. Dalton didn't get sacked once and the Chiefs didn't get a single quarterback hit on him. He finished 17 of 24 for 321 yards and a touchdown.