The San Francisco 49ers are 2-2 after knocking off the New England Patriots 30-13. San Francisco was in control throughout and the result was never in doubt, but the sloppy nature of the Niners' performance shouldn't make them feel much better about what, by their standards, has been an underwhelming start.

There was a lot to like about the 49ers' performance, they had four huge pass plays of over 30 yards, the run game thrived with Jordan Mason averaging 5.1 yards per carry in a 123-yard effort that saw him find the endzone again, and a defensive line missing Javon Hargrave utterly dominated a severely undermanned Patriots offensive line, registering six sacks.

And yet the 49ers leave this game with plenty to clean up.

San Francisco could rightly be accused of playing with their food in a severely one-sided contest.

The 49ers fumbled three times, with the most glaring error in that regard coming on special teams as rookie Isaac Guerendo lost the ball on the opening kick return of the second half, setting up a Patriots offense that averaged just 3.5 yards per play with a short field from which to score their only touchdown.

On top of that, San Francisco was far from convincing in the red zone, going two for four inside the Patriots' 20-yard line, and wasted an opportunity to put the game well beyond doubt in the fourth quarter when Brock Purdy, having guided the 49ers to the Patriots' 23-yard line, was picked off in the endzone. Purdy paid the price for an ill-advised throw into double coverage as he attempted to force the ball to Brandon Aiyuk.

"I don't want him to throw into double coverage," head coach Kyle Shanahan said of that Purdy error. "There was a busted route on the backside, I didn't like how late it [the throw] was."

It ultimately did not matter as the defense had little issue ensuring the Patriots would not even threaten a dramatic fightback effort. 

San Francisco's defense forced three turnovers, including a pick-six from All-Pro linebacker Fred Warner to further his Defensive Player of the Year cause.

"I thought the defense was awesome all day," Shanahan said, describing an overwhelming effort that was in stark contrast to the porous performances the Niners produced on that side of the ball in defeats to the Los Angeles Rams and Minnesota Vikings.

Yet, such are the Patriots' injury issues that the 49ers' performance on defense must be taken with at least a small pinch of salt and, with Warner sitting out the second half with an ankle injury, there is some reason for concern on that side of the ball. 

Shanahan said afterward that he did not know the severity of Warner's injury, though he did confirm defensive tackle Jordan Elliott had avoided an ACL injury after leaving the game with a knee issue.

The 49ers played a dominant game, but it was not a clean game. To the contrary, it was one where they threatened to give the Patriots late life. 

San Francisco can play much, much better than this. Winning so convincingly in Week 4 with a performance that was far from perfect can be considered reason for encouragement. However, any optimism from this showing should be tempered at least somewhat. 

Indeed, the same issues on special teams that played a huge role in the losses to the Vikings and Rams remain, the injury list has grown and the offense, for all its production, needs to improve its overall execution.

Said Purdy: "We can all, collectively as an offensive unit, be better."

History says the 49ers will clean things up on offense. With tougher tests lying in wait, that needs to happen sooner rather than later. It won't be clear whether the defensive revival is real until the 49ers face those sterner examinations.

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