CINCINNATI -- Believe it or not, perhaps the most difficult throw San Francisco 49ers quarterback Jimmy Garoppolo made in Sunday's win against the Cincinnati Bengals was the one in which his intended target was the most open.

On the Niners' fourth play from scrimmage, wideout Marquise Goodwin leaked down the left sideline and suddenly found himself with a whopping 13.2 yards of separation from the nearest defender, according to NFL Next Gen Stats. Garoppolo didn't need one of his best throws for a walk-in touchdown -- he just needed not to blow the layup.

"It's not hard, but it's just nerve-racking," Garoppolo said. "Because you're like, 'If I miss this one, I'll be on SportsCenter Not Top 10.'"

Garoppolo managed to hit Goodwin for a 38-yard touchdown, which is the most open score by an NFL receiver this season and the most open touchdown for a 49er since 2016.

It would also be far from the last layup Garoppolo was able to make in the 41-17 blowout. In fact, it was a harbinger of things to come, as Niners coach Kyle Shanahan pressed all the right buttons, got a strong performance from his offensive line and watched his offense explode for 572 yards, the most for the Niners since Oct. 7, 2012. They averaged 8.41 yards per play, the most since Nov. 6, 2016.

There are many things that can make Garoppolo's return from the torn left ACL that cost him 13 games in 2018 easier, but Sunday's game offered a resounding reminder that Shanahan can play a key role in making that happen.

"It makes my job very easy," Garoppolo said. "His mind is incredible, just how he thinks. He's two plays ahead while we're running the current play and it makes everything so easy. And when he gets in a rhythm like that, it just puts everyone in a good position."

A week after a disappointing offensive performance against Tampa Bay in which Shanahan didn't ask much of Garoppolo, the head coach -- along with assistants Mike LaFleur and Mike McDaniel -- dialed up a creative, balanced game plan.

What followed was a series of big plays that left Bengals defenders scratching their heads and gasping for breath. The 49ers finished with six pass plays of 20-plus yards and nine runs of 10-plus yards. Bengals cornerback William Jackson said the Niners "used every trick in the book" and noted that San Francisco "clearly plays some Madden."

While Shanahan didn't hesitate to reach into his bag of tricks -- including a throwback pass from receiver Dante Pettis for a 16-yard gain -- the Niners really didn't do all that much different. They just did what they ordinarily do extraordinarily well.

"When he gets in a rhythm, whatever personnel is out there -- even if we haven’t game planned to go that many plays in a row -- he just keeps it out there and he keeps it going," fullback Kyle Juszczyk said. "He likes to keep his foot on their throat."

In Garoppolo's second regular-season game back since the injury, he finished 17-of-25 for 297 yards with three touchdowns and one interception for a passer rating of 131.2, his best since arriving in San Francisco in 2017.

The key to it all? Success on early downs. The 49ers rarely found themselves facing third-and-long, or third down at all. They were 5-of-9 on third down and compiled 500 of their 572 yards on first and second down, averaging 8.5 yards on those plays. The offensive line didn't allow a sack, yielded just two quarterback hits and opened holes for a running game that finished with 259 yards on a robust 6.2 yards per carry.

Avoiding third down or third-and-long allowed Shanahan to avoid becoming one-dimensional. Garoppolo and the offense reaped the benefits.

"When you stay in front of the chains like we did today, Kyle gets to use his whole book, which is dangerous for everybody else in the NFL," right tackle Mike McGlinchey said. "We controlled the chains today, we controlled the ball, we controlled the line of scrimmage, and that's all we want to do. We were able to stay in our base stuff and didn't have to panic or anything like that and that's why we had a lot of success today is because we came out on first and second down and executed well and got the job done."

That's not to say that Garoppolo didn't offer encouraging signs that he's recovered from the torn ACL and poised for further improvement. In a day full of big plays, none stood out more than the first offensive snap of the second half.

On the play, Garoppolo took the snap and dropped back as the Bengals generated some rare pressure. As Cincinnati defensive tackle Ryan Glasgow bore down on Garoppolo, he took a step forward and fired a dart to receiver Deebo Samuel, who gained 39 yards on the play. Garoppolo took the hit, bounced back up and the Niners scored six plays later.

In a day full of bigger, fancier plays, it was a notable moment in Garoppolo's recovery.

"It's good to get hit, I guess," Garoppolo said. "It sounds weird to say, but it's moving in the right direction."

With Shanahan at the helm, Garoppolo's progress might accelerate faster than expected.