Daniel Shirey / Stringer

SANTA CLARA — The 49ers drubbed the visiting Oakland Raiders, 34-3, Thursday night, notching San Francisco’s second win of the season.

Here are five takeaways.

The 49ers clicked on all cylinders for the first time all season

With exception to San Francisco’s 39-10 loss to the Los Angeles Rams, the 49ers had a chance in every game. Their losses and sole win (prior to Thursday) were marred with slow starts or poor finishes.

The 49ers undoubtedly played their most complete game all year.

After two Nick Mullens-led touchdown drives, they controlled the game. They led, 17-3, at halftime. Then they poured on two more touchdowns to put the game out of reach with more than one quarter left.

The win was a team effort. The offense compiled 405 yards, with a healthy mix of passes and rushes. The 49ers defense allowed just 248 yards. The pass rush produced seven sacks. And the 49ers did not turn the ball over for the second straight game, which is a sign of progress.

The Raiders looked completely uninspired

At some point during Thursday night’s shellacking, it was reasonable to wonder whether the Raiders players were giving their full effort. The 49ers played better, but they seemed to easily rip off big gains after struggling to yield much of any offensive production one week ago, against a subpar Cardinals defense.

The play Thursday night that stood out was 49ers running back Raheem Mostert’s 52-yard touchdown run. Mostert took a toss to the right and ran untouched up the sideline into the end zone. The majority of the Raiders defense trailed on the other side of the field, with no apparent sense of urgency to catch Mostert.

Richie James’ 53-yard catch raised similar questions. The Raiders blitzed, and James ran a slant, caught the pass, and ran upfield for the big gain.

At 1-7, the Raiders now have tied for the worst record in the NFL. They have traded away several of their most prominent assets. With the playoffs seemingly out of sight, it did not look like the Raiders were playing for much of anything Thursday night.

Nick Mullens was the spark plug the 49ers had lacked

Yes, the Raiders looked disinterested. Yes, their defense had allowed more than 31 points per game on average, the second-most of any team this season. Oakland has been torched all year.

But Mullens deserves a ton of credit for his prolific NFL debut.

Mullens was named the starter with C.J. Beathard still recovering from a right wrist injury. Beathard was the backup Thursday night, but the 49ers did not need him.

Mullens completed 16 of 22 passes for 262 yards and three touchdowns. With exception to one questionable throw in the end zone that was nearly intercepted, he played nearly a perfect game. His 151.9 rating was 6.4 points away from perfection.

Mullens was accurate, hitting his receivers in congested areas. He was decisive, getting rid of the ball in the face of pressure, notably on a 53-yard completion to James late in the second quarter. And perhaps most importantly, he did not commit a turnover, contrary to Beathard’s 12 turnovers in five starts this year.

Mullens led the 49ers to touchdown drives on their first two offensive possessions, the first time that has happened all year. He played a smart game thereafter.

Mullens took advantage of his first NFL start, potentially propelling himself into the starting role in Week 10. Regardless, at least he’s verified on Twitter now.

The pass rush was the best it has been all season

The 49ers entered Thursday with just 16 sacks through seven games. The lack of pass rush has trickled down to the rest of the defense, forcing the secondary to cover for longer periods of time.

Thursday night proved how a productive pass rush affects everything else. The 49ers compiled seven sacks,  more than doubling their previous single-game totals this season.

They benefited from Dekoda Watson’s return. Watson was activated off the injured reserve list earlier Thursday. By night’s end, he had 1.5 sacks and was in the area for several more opportunities.

Cassius Marsh, who has disappeared for long stretches this season, produced the best performance of his career. He had 2.5 sacks, two tackles for loss, and a forced fumble the Raiders recovered early in the fourth quarter.

Richie James played well in the first extended action of his NFL career

With starting slot receiver Trent Taylor inactive, another rookie took advantage of his first extended NFL action.

James, one of San Francisco’s two seventh-round picks in 2018, caught two passes for 60 yards. Late in the second quarter, he turned a short slant upfield for 53 yards, which ultimately led to a touchdown. On the following play, James caught a seven-yard pass. The only blemish on James’ night was a dropped pass one play later.

James was San Francisco’s best receiver in the preseason, but he had minimal opportunity prior to Thursday. His performance should involve him in the receiver rotation more moving forward, particularly if Taylor misses more time.