One thing has become very clear during the 49ers' 5-0 start: The defense is legit. 

Defensive coordinator Robert Saleh's unit put together another masterpiece Sunday when they held Jared Goff to 78 yards passing in a 20-7 win over their NFC West rivals.

Through five games, the 49ers defensive line has terrorized opposing quarterbacks, notching 17 sacks and holding opposing offenses to a 29.5 percent third-down conversion rate.

So, now let's think back to the preseason when Jimmy Garoppolo threw five straight interceptions during practice. It all makes sense now if you ask George Kittle.

“I was thinking in the third quarter while watching our defense play, ‘Huh, maybe this was the reason Jimmy threw those five interceptions in practice,'" the tight end said after the win in LA, via ESPN's Jeff Darlington.

Fair point.

While Garoppolo has been far from perfect this season, the internet panic button that was pressed after that horrid practice appears to have been premature.

Now 13-2 as an NFL starter, Garoppolo has thrown for 1,162 yards, seven touchdowns and five interceptions so far this season. Coach Kyle Shanahan undoubtedly would like Garoppolo to clean up some of his mistakes -- like the head-scratching pick he threw in LA on Sunday -- but Garoppolo has performed adequately in the early going.


[RELATED: Kittle jokes about Jimmy G's looks before throttling Rams]

Garoppolo still has some rust to knock off after missing most of last season with a torn ACL, but the defense has proven more than capable of carrying the load.

The combination of Nick Bosa, DeForest Buckner, Arik Armstead and Dee Ford has proven too much for opposing quarterbacks to handle. Something Garoppolo for sure knows all about.

Garoppolo and Kittle are just glad they are on their side on Sundays.