In a game where many believed that the San Francisco 49ers needed to prove themselves, they did more than that with a 20-7 victory over the Los Angeles Rams. Their win over last season's NFC champions is something that will continue to silence a lot of the doubters that have labeled the team as pretenders.

They continue their rise up many power rankings and prove that they are for real this season. But making the leap up in some rankings and having Richard Sherman continue to call out critics that believed the 49ers weren't going to go anywhere aren't the only things that we've seen from the team's week six win.

Here are the three things we learned about the San Francisco 49ers from their win.

3. The 49ers have the best defense in the NFC (and maybe in the league)

San Francisco held the Rams to just seven points. Los Angeles averaged 29.2 points per game before Sunday.

The 49ers didn't allow a single third- or fourth-down conversion, forcing the Rams to go 0/13 in that category. And most impressively, they held Sean McVay's offense to less than 250 total yards in his entire tenure as head coach (157).

They're first in their conference in both yards allowed per game (237.4) and points allowed per game (12.8). It's a significant improvement from where the 49ers were last season, and it shows how much the key acquisitions helped.

2. The Offense wasn't pretty this week but they continue to get the job done

The 49ers didn't dominate with the rushing attack (99 rushing yards) like they were before this game. They scored far less points than they should have with how they controlled the clock (38 minutes and 52 seconds) and with the amount of red zone trips that didn't lead to touchdowns (two-of-five).

Kyle Shanahan's offense wasn't overtly flashy or something that led to many points last Sunday. Instead, they resorted to dominating the time of possession and taking advantage of what their defense gave them. Jimmy Garoppolo managed the game the best way he could by moving the sticks. They were 9/18 on third- and fourth-down conversions (8/17 on third), and they came away with 22 first downs as well.

It wasn't a major scoring output by Shanahan's offense, but they still got it done. And that's all that matters.

1. The San Francisco 49ers are Contenders

For the longest time critics kept saying that the 49ers hadn't played anyone difficult yet. Before Sunday, the 49ers had played against four opponents that had a combined record of 5-15. And many experts went on to call them pretenders constantly.

But after winning on the road against last season's NFC Champions that featured San Francisco as underdogs. And they came away with a dominant performance against a favored Rams team that's expected to go back to the Super Bowl.

The team has a brand new swagger to them, and are using the people that doubted them as fuel.

This is a team that will only continue to make waves as the season goes along as they show that they are the team that they know they are.