The St. Louis defense was able to create solid pressure and the unit held strong in the red zone, limiting the 49ers to field goals for the most part. But lack of production on offense killed the Rams.
Throw in numerous dropped passes and a bundle of killer penalties early on, and it's not hard to figure out how the Rams let this game get out of hand.
The Rams will have a shot at redemption next week against the tough Arizona Cardinals, while the 49ers will attempt to maintain their Wild Card lead over Arizona when they host the division-leading Seahawks next Sunday.
For now, here are my takeaways from St. Louis' loss to San Francisco.
This game was déjà vu for the Rams in terms of penalties.
St. Louis has played more disciplined football in recent weeks, but this game was reminiscent of the first five games of the season, when penalties crippled the Rams.
The defense racked up five penalties in the first quarter alone. The Rams finished with 11 total penalties for 105 yards.
It's hard to beat a tough team on the road with such sloppy play.
Kellen Clemens finished the first half of the game with a 33 percent completion rate with just 37 passing yards. He completed only 51.3 percent of his passes overall.
Zac Stacy was held to 25 yards and a 2.5 yards-per-carry average in the first half, but he improved in the second half with nine carries for 47 yards (5.2 yards per carry).
Every Rams receiver was held under 50 receiving yards.
If you're part of the small minority hyping up Clemens as an upgrade over Sam Bradford, you might want to seriously reevaluate your position.
Clemens has surprised us with his shockingly solid play, but his outings against Chicago and Indianapolis were the two best statistical games of his eight-year career. It was foolish to believe he'd maintain that level of play for more than a few games.
This game was a much more accurate depiction of what the post-Bradford offense looks like.
Sure, the defense had five penalties in the first quarter alone and allowed Colin Kaepernick to complete 71.4 percent of his passes in the first half and 68 percent overall, but at least the defensive line is still fierce.
With four total sacks in the game, it appears that the St. Louis pass rush is consistent and can be counted on every week.
Although the Rams will likely finish the year with a losing record, it's a small consolation prize to know that the St. Louis front eight is capable of punishing quarterbacks on a weekly basis.
Michael Brockers is a streaky player and is invisible at times, but he's quietly posting impressive numbers.
With two sacks in San Francisco, Brockers now has a career-high 5.5 sacks this season with four games to go.
Brockers will eventually learn how to play with more consistency, and when he does...watch out.
This was the 45th game at Candlestick between the Rams and the 49ers, and the two teams entered the series tied 21-21-1.
Unfortunately, this was the final game at Candlestick between these two teams, so the 49ers win the overall battle for Candlestick dominance.
But there's no need to worry; the Rams will have every opportunity to dominate the 49ers in their new stadium.
This rivalry isn't going anywhere.
Chris Givens dropped a key pass in the third quarter. Clemens lobbed a ball that hit Givens directly in the hands, but he dropped it.
It was a pass you'd expect an amateur player to make. With no 49ers in the area, Givens arguably had a shot at running the ball into the end zone, but he failed to make the potentially game-changing play.
Givens was hyped during the preseason at St. Louis' most dangerous deep threat. He had five receptions of over 50 yards in 2012. But the second-year receiver has zero in 2013.
Givens has zero touchdowns this season and has just one reception over 30 yards since Week 2.
It's hard to pinpoint what exactly is troubling Givens, but it's clear he's one of several Rams players who have regressed in 2013.
We saw the Rams run a fake punt against the Dallas Cowboys in Week 3, and that went horribly wrong. The Rams ran the same fake against the 49ers in this game, and the result was equally troubling.
It's clear that this Rams team is incapable of running a successful fake, unlike the 2012 squad.
Hopefully, Rams special teams coach John Fassel can wake up and resist calling another fake punt, especially when failing gives the opponent the ball inside the 20.
After St. Louis' rough start to the season, the playoffs were a remote possibility, but a possibility nonetheless.
With Arizona's loss to Philadelphia, the Rams had a chance to upset San Francisco and move just one game behind the Cardinals and 49ers in the Wild Card race.
Had they won the game, it still would have been an uphill battle, but the momentum could have resulted in something remarkable.
Instead, the Rams suffered a devastating loss. A loss that reminded us that the Rams are still building, and that Clemens is no Bradford.
Most St. Louis fans were hoping that the Rams could muster some late-season magic to make things interesting at the very least, but it appears this season will once again be about moral victories instead of tangible results.