Marvin Lewis' squad had won four straight. In each of the final three, quarterback Andy Dalton had thrown for at least 325 yards and three scores.
Alone atop the AFC North, not many gave the Dolphins—owners of a four-game skid—a legit shot.
However, Miami responded to Cincinnati's mistakes when the game was on the line. Defensive end Cameron Wake nailed Dalton for a sack to win the meeting in overtime for just the third time in history.
Here are a few of the biggest takeaways from the major loss.
So there it is.
After three amazing performances—one part outstanding strategy from offensive coordinator Jay Gruden, one part stellar play from under center—it appears Andy Dalton is still human.
Remember, Dalton traveled to Miami just days after throwing five touchdowns in a rout of another AFC East team.
Dalton came crashing back down to earth against the Dolphins. Yes, he threw for 338 yards, but two of Dalton's three costly interceptions were horrific, rookie-esque mistakes.
One was even returned for a touchdown, as shown by the NFL on Twitter, surely giving the Cincinnati faithful flashbacks to its last franchise quarterback:
Dalton is a good signal-caller, but he's seriously prone to pivotal mistakes. It's been on full display all season, and it's up to the play-callers to limit them, because Dalton can't seem to help himself at times.
Forget for a moment that a holding call on Jermaine Gresham was questionable.
Instead, focus on the fact Gresham's penalty negated a touchdown (in a game that went to overtime), and the end result of the drive after the penalty was Andy Dalton's pick-six.
The play was already past Gresham and he had no business engaging a defender in the first place. He shouldn't have put himself in the position to be flagged, plain and simple.
Gresham leads all tight ends in the NFL with eight penalties.
It's time to start asking whether or not Gresham needs to consistently be on the field outside the red zone. There's a better pass-catching tight end on the roster in Tyler Eifert and a better blocking one in Alex Smith.
This one hurts.
Per NFL Network's Michael Silver, Cincinnati defensive tackle Geno Atkins appears to have suffered a torn ACL after he awkwardly planted his foot during the contest with Miami:
Make no mistake—Atkins is arguably the best defensive tackle in the NFL. His presence makes those around him better.
Whereas Cincinnati could effectively scheme around the loss of corner Leon Hall, there is absolutely nothing the team can do to replicate the impact Atkins has on each game.
The jobs of the linebackers behind Atkins just became much more difficult, as did the jobs of every defensive lineman who will now see more attention with one of the NFL's most dominant forces out of the picture.
Cincinnati's run defense was once again suspect this week against Miami, and that was noticeable before Geno Atkins was lost to a knee injury.
In total, the Dolphins were able to rack up 157 total yards on the ground. Lead back Lamar Miller went for 105 and an impressive 6.6 per-carry average.
A dip in the run defense department was a bit expected with starting middle linebacker Rey Maualuga out for the game with an injury, but Miller consistently getting to the edge and subsequently up the field is not a typical day for the Cincinnati defense.
Even worse, Miller was having a subpar season at best. The output is his best yardage effort of the year.
With Atkins out of the picture, the run defense has a lot of soul searching to do.
Cincinnati Bengals rookie running back Giovani Bernard can change the course of a game on a dime.
In perhaps one of the greatest runs in recent memory, Bernard showed this skill off in impressive fashion.
Per NFL Network:
Giovanni Bernard's got a bright future if he can keep making moves like this. WATCH: http://t.co/jNezFXLGGq— NFL Network (@nflnetwork) November 1, 2013
Bernard finished with 79 yards on just nine carries and scored the two touchdowns that would force overtime before he missed the rest of the game with a rib injury, per Joe Reedy of the Cincinnati Enquirer.
There is a double-edged sword at play here, though.
On one hand, it only seems right to clamor for coordinator Jay Gruden to use Bernard more given what he is capable of at any point. On the other, his seemingly minor injury is what can happen when a smaller back receives too much work.
As CBS Sports' Dave Richards points out, the Bengals are a better team with Bernard in the lineup:
Gruden's gotta realize the offense is tougher for defenses to predict w/ Gio back there instead of BJGE. They can run anything w/ Gio.— Dave Richard (@daverichard) November 1, 2013
Regardless, the Bengals have a budding star in the backfield for the first time in over a decade.
When will it stop?
Injuries currently litter the Cincinnati Bengals roster with no end in sight. Cornerback Leon Hall was lost for the year, and he was the best slot corner the NFL had to offer. Meanwhile, the aforementioned injury to Geno Atkins crushes the unit as a whole.
Unfortunately, NFL Around the League's Chris Wesseling puts it best:
Two days after placing their top defensive back on I.R., the Bengals lose their best defensive player while their best RB sits out overtime.— Chris Wesseling (@ChrisWesseling) November 1, 2013
Cincinnati is one of the deepest teams in the NFL, but any roster can be hit in the right spot to make everything come crashing down. The Bengals have now lost their two best defensive players and the team is only nine games into the season.
Amid the wealth of bad news for the Cincinnati Bengals, there are plenty of bright spots to examine, including young talents.
Perhaps the most important among this group is A.J. Green, who once again elevated his play and his team to impressive heights despite mediocre play from quarterback Andy Dalton.
A.J. Green has his 3rd career game with 10+ catches, 4 straight 100-yard receiving games. pic.twitter.com/CnLQxbAldy— SportsCenter (@SportsCenter) November 1, 2013
Green, despite being blanketed by stud corner Brent Grimes for most of the contest, caught 11 passes on 19 targets for 128 yards. Most impressively, six of Green's receptions came on third down.
After a lackluster performance a week ago likely by design, Green went off in prime time. Unfortunately, he simply cannot do it all on his own.
The Cincinnati Bengals roster that was one of the NFL's best teams with a 6-2 record through its first eight games is no more.
Gone is star corner Leon Hall and arguably the best interior lineman in the NFL with Geno Atkins' injury.
Outside of injury issues, the heartbreaking loss to Miami ever-so-slightly opens the door for Baltimore in the AFC North, as Cincinnati must now turn around and hit the road for a matchup with the defending champs.
Any time a game ends in this fashion, major issues are on the horizon (via NFL Network):
With Andy Dalton's struggles, injuries and a brutal schedule the rest of the way that includes Baltimore twice, Indianapolis, San Diego, Pittsburgh and Cleveland, the Bengals may find it difficult to replicate the success of the first half of the season.