The San Francisco 49ers defeated the Los Angeles Rams 24-9 on Monday Night Football, becoming first place in the NFC West as a result.
While the 49ers won with significant measure, it was the defense that shined once again, limiting the Rams to nine points and scoring a touchdown to seal the game.
Here are the defensive grades from Week 4.
Defensive Line: A
With Javon Kinlaw not suiting up due to a knee injury and Arik Armstead playing just 41% of the defensive snaps, you'd expect the 49ers defensive line to potentially take a step back.
The unit did the exact opposite on Monday Night Football, dominating the depleted Rams' offensive line at every position, en route to eight sacks and 35 pressures on the day. Yes, that's not an exaggeration.
Nick Bosa showcased why he's an early candidate for Defensive Player of the Year, accumulating 14 pressures and two sacks, while sporting a pass-rush win rate of 36.4%.
Samson Ebukam and Charles Omenihu continued their excellent play in their respective roles, with the former recording four pressures, two sacks, and the game-sealing forced fumble, while the latter had five pressures and a sack.
The 49ers had four different players(Bosa, Ebukam, Omenihu, and Kevin Givens) accumulate a pass-rush win rate of over 20% on their own, illustrating their superb performance in the defense's best game of the year thus far.
Against the run, the 49ers had 11 run stops and zero missed tackles, playing efficient football and limiting the Rams to an ineffective 3.2 yards per carry.
This 49ers defensive line is scary enough without Arik Armstead and Javon Kinlaw, so imagine the results when both players return fully healthy.
Linebackers: A
Fred Warner and Dre Greenlaw both played spotless games once again, with the former recording nine tackles and the latter recording a team-high 15 tackles against the Rams.
Warner's ability in coverage continues to be underappreciated as the linebacker wiped out receiver Cooper Kupp on several routes with his instincts in zone coverage.
Both players had two run stops each, while neither missed a single tackle on the day, despite their high volume.
What makes their performances even more impressive was the fact that both players played all 74 defensive snaps for the SECOND week in a row, yet they kept their intensity up in two strong performances.
While Azeez Al-Shaair has been injured, both Dre Greenlaw and Fred Warner have played every single defensive snap this year.
If Greenlaw continues to play at the level he's currently at, his two-year extension will certainly bode well for the 49ers, who are already reaping the benefits from their emerging linebacker.
Cornerbacks: A-
Similar to the linebackers, all three of the 49ers' starting cornerbacks played every snap defensively in Week 4, as the 49ers remained in their nickel defense for the entirety of the game.
Deommodore Lenoir, San Francisco's new nickel cornerback, faced the tough task of guarding receiver Cooper Kupp, and while the esteemed wideout had 14 catches for 122 yards, the second-year defensive back held opposing receivers to an average target of depth of just 4.5 yards.
Additionally, Lenoir recorded a pressure off of an effective nickel blitz, while having a run stop as well on Monday.
Charvarius Ward continues to be a lockdown corner on the outside, playing strong coverage, while also being a consistent tackler when provided opportunities.
In 22 tackle opportunities this season, Ward hasn't missed a single one yet, speaking to his reliability not only in the passing game, but when players are in space.
Like Ward, Emmanuel Moseley continues to be a strong secondary cornerback and is playing his way into a significant raise this offseason when he can hit the open market as a free agent.
Overall, the 49ers limited Matthew Stafford to just 5.3 yards per attempt and 5.1 air yards per attempt, meaning he was forced to take more conservative throws due to the downfield coverage.
Lenoir's play will be something to monitor over the next few weeks, as I'd expect teams to consistently target the slot with how Ward and Moseley have played on the outside.
Safeties: A
Talanoa Hufanga has emerged as a star safety and his interception, which involved elite play recognition, burst, and vision, sealed the deal, as well as the 49ers' 24-9 victory over the Rams.
Hufanga's ability to process and enact on plays has propelled an assumed area of weakness into a significant strength for the 49ers, and Tashaun Gipson's surprising play only adds to the factor.
Hufanga's aggressiveness can occasionally lead to missed tackles, but with the way that the 49ers are able to make plays, there's usually a player to clean it up and record the stop.
Still, Hufanga's emergence has provided new energy for the 49ers and DeMeco Ryans's playcalling consistently puts his young safety in the best place to make plays.
Gipson continues to man the back end, but was even seen near the line of scrimmage for a few snaps, where he recorded a run stop of his own.
With Jimmie Ward returning to practice this week, the 49ers may have themselves a valuable three-safety rotation that could allow more ingenuity from Ryans, giving different players a rest, while keeping his best groups on the field.