EARTH CITY, Mo. -- Moments after his defense had held an opponent to just six points for the second consecutive week, St. Louis Rams coach Jeff Fisher told them that the six points-per-game average isn't good enough. Seriously.

“I told the guys inside, ‘12 points in two weeks is too many,’" Fisher said. "That’s the approach you have to take. We got off the field on fourth down a couple of drives and once they get down there, we’re stressing field goals, field goals, field goals."

But to hear Fisher's players tell it after the game, even those field goals are unacceptable. That's the standard that coordinator Gregg Williams has set for his defense. And it's in that standard that the Rams are finding their motivation to become the type of dominant defense that many thought they would be before the season.

In Sunday's 27-6 victory over the San Francisco 49ers, the Rams left the Niners offense looking every bit the anemic group that it's been for most of the season, perhaps more so. The result left only six points on the Niners' side of the scoreboard as well as 189 yards of offense, the third-fewest allowed by a Rams defense since Fisher took over as coach in 2012.

San Francisco averaged just 2.91 yards per play Sunday, which is the lowest allowed by a Rams defense since Fisher took over and by any Rams defense since ESPN Stats & Information began tracking such data in 2001.

So even when the Rams offense has struggled to perform -- and it has -- the defense has been there to keep things close.

“Oh, it’s awesome," quarterback Nick Foles said. "I’m the defense’s biggest fan in the world. Watching what those guys do. Say it over and over again, ‘It’s a team game, but I’m a fortunate quarterback to have a defense like we do.’ Those guys keep working. They have a great leadership. We keep pushing each other every day. So, we have a great team here that just has to keep pushing each other to get better.”

At the heart of that team is a defense that was built to be the focal point of the franchise. Whether through the addition of Williams as coordinator, having five first-round picks on the defensive line or the patience to develop a young secondary, the Rams defense is finally starting to put all the pieces together nearly three-and-a-half years into Fisher's tenure.

The Rams rank sixth in the NFL in yards allowed per game (328.1), fifth in yards per play allowed (4.97), sixth in yards per carry allowed (3.73), ninth in yards allowed per pass attempt (6.39) and tied for second in sacks (26).

All of those numbers are impressive in their own right and a product of what middle linebacker James Laurinaitis calls a group playing disciplined, selfless football in which the good of the unit is placed above individual statistics.

They're also the result of a group that takes its cues from Williams, who demands nothing less than a shutout every week.

"We don’t want to give up any points," safety T.J. McDonald said. "Definitely not touchdowns, but we want to keep them out of the red zone. We just hold ourselves to a high standard and I think that all great defenses do. We want to be a great defense. We have a very good defense, but we want to be great. We’re not quite there yet, but if we keep holding ourselves to that standard, I think we can get there."

To get there, it requires some nitpicking. But the Rams could still stand to cut down on the completion percentage allowed (70.6 percent is third-worst in the league though most of those have been short passes) and the defensive penalties, as the 25 flags thrown against them is tied for 13th-most in the NFL. It also wouldn't hurt to get defensive end Chris Long back from a knee injury and, perhaps eventually, get linebacker Alec Ogletree back from his fractured fibula late in the year.

“I think we can be a lot better," McDonald said. "I think we’re barely scratching the surface. Every time we go out there and watch the film, some of the points they have scored it’s been because of our mistakes, not anything they’ve done. You can give some credit to the other team, but I think that we can be a lot better and we’re continuing to do that, continuing to study, continuing to get better as a defense and I think we’re jelling well, buying into the system and I think that we’re going to get a lot better.”