The victory keeps the Bengals playoff hopes alive, but with a less than confidence-inspiring performance, they may be on life support.
Here's what we learned from Sunday's game.
Despite a late TD to seal the game for Cincy, Cedric Benson was kept largely in check by the league's worst rushing defense, mustering only 76 yards for the day.
Unfortunately for Ced, the limited carries that Bernard Scott saw were arguably more impressive than Benson's, as No. 32 fumbled three times during Sunday's action.
With the former bell-cow running back unable to find any sort of consistent form following a year plagued by legal woes, it seems as though this will be Ced's final year in stripes.
His one-year deal is unlikely to be renewed for 2012.
That being said, Benson still has two games in which to contribute to the playoff effort. With the need to play for a contract next year—wherever that may be—Benson will be desperate to impress at home against Arizona and Baltimore.
Expectations for Ced are somewhat tapered nowadays, but the ball is very much in his court. Time to step up.
After the ropey display put on by the Bengals secondary the last two weeks, the return of Nate Clements to the lineup was a welcome relief for Bengals fans and DC Mike Zimmer.
Clements made his presence felt on Sunday by racking up seven tackles and a blindside sack to Kellen Clemmens that left the third-string QB on the ground seeing stars.
Clements locked horns with veteran RB Steven Jackson on a number of occasions, and helped to keep the RB in check throughout Sunday's action.
Clements' production was good on the day, and you have to like the reassurance he brings to the otherwise shaky secondary. His presence is as important as his output. The vet brings an intensity to the secondary that has been missing since Leon Hall's injury.
Nate Clements is back, and he will prove to be an important asset for Cincy in their final two games of the year.
It may have taken him 15 weeks, but Brandon Tate found his feet on Sunday in St.Louis, making a big contribution to the Bengals winning effort en route to a franchise record 481 yards this year.
The polarizing kick returner has had a slow year, and had provided little spark on special teams prior to Sunday.
However, his 56-yard punt return set up a Bernard Scott touchdown, allowing Cincy to begin heaping dirt on St.Louis.
Tate was productive throughout the day and put the nail in the coffin by recovering a Rams onside kick at the death to seal things out.
Tate gave the Bengals a much-needed special teams boost on Sunday, looking like the player Marvin Lewis had hoped for in the offseason.
If he can keep it up, his contribution will be greatly appreciated in the next two must-win games.
Mike McGlynn replaced injured veteran RG Bobbie Williams on Sunday to the collective shudders of Bengals fans.
He had two penalties on the day, putting in a sub-par performance as expected. Growing pains are likely for McGlynn—who struggled early in the year when Bobbie Williams served a three-game suspension.
The stats don't tell the whole tale, and McGlynn's weakness (as well as Anthony Collins'), was largely the reason why Cedric Benson was so ineffective in the run game on the right side.
McGlynn's play will be a primary concern for Marvin Lewis and Andy Dalton with Baltimore looming at the end of the year.
The veritable weak-link in the Bengals offense is painfully obvious, and it will take some quick learning from McGlynn to get up to pace so late in the day.
A.J. Green has been one of the most exciting rookies in the NFL for quite some time, and he continued to provide excitement against the Rams despite battling a third-degree shoulder sprain.
Green had six receptions for 115 yards, taking him over the 1,000 mark for the year. He showed once again why he could be Pro Bowl bound in his rookie season.
Andy Dalton relied on Green's playmaking ability significantly in this one, so current injury worries are a cause for concern going forward.
It may not have been a particularly pretty affair for the most part, but Andy Dalton and A.J. Green made history against the struggling Rams, becoming the most prolific rookie WR/QB since 1991.
The duo have hooked up impressively in 2011, and have received well-earned plaudits because of it.
The former record holders, Tim Couch and Kevin Johnson put up 859 yards off of 57 catches, which has now been surpassed by Green/Dalton with 58 receptions for 951 yards.
In what was expected to be a dismal season in Cincinnati, the progress of Andy Dalton and A.J. Green has been nothing short of outstanding. Their veteran-like connection bodes well for the future, and Bengals fans have a lot to look forward to.
It is also noteworthy that Andy Dalton now has the fifth most rookie passing yards in league history, following a 179-yard showing in St.Louis.
The Bengals were a woeful three for 11 on third down, with a blisteringly bad 27 percent efficiency.
Third downs have become a concern in recent weeks as the offense continues to struggle to maintain its early success.
The Bengals commitment to Ced Benson and the running game on third down was their main problem, especially with some terrible play from the offensive line.
It's a tough situation for Jay Gruden, who wants to be able to lean on Cedric Benson in these situations. Unfortunately, the offensive line can't provide him with gaps, and it often results in a fourth down.
With backups on the offensive line for the foreseeable future, this could continue to prove sticky for the offense.
As mentioned in the opening slide, the Bengals went a long way towards beating themselves on Sunday afternoon with penalties occurring at an alarming frequency.
The Marvin Lewis era has been synonymous with yellow flags, and the old adage that "old habits die hard" seemed apt in St.Louis.
The Bengals racked up 11 penalties for 101 yards, only narrowly beating the equally sloppy Rams with 10 for 109 yards.
The Bengals have the ability to play great football. However, too often they shoot themselves in the foot moments later with a foolish penalty. It continues to be a problem that has seen little in terms of a resolution.
St. Louis may not have been the sort of team to capitalize on these mistakes, but with two must-win games ahead of the Bengals, there's no denying that Arizona and Baltimore will.
The over-reliance on A.J. Green coupled with the blood-draining from Bengals fans' faces when he got hurt was enough to expose one thing: The passing game has struggled lately.
Jermaine Gresham was notable only for penalties in St.Louis, while Jerome Simpson and Andrew Hawkins failed to make an impact.
While Andy Dalton and A.J. Green may be making the highlight reel every Sunday—and commended on NFL Network continuously—they can't do it all on offense.
Dalton needs to find consistency with his No. 2 receiver Jerome Simpson: He has become somewhat of a non-factor when A.J. is present.
Green accounted for a whopping 64 percent of the Bengals passing offense on Sunday, both an impressive and worrying statistic.