The San Francisco 49ers hammered the Cleveland Browns on Monday night, defeating them by a score of 31-3 to improve to 4-0 on the season in front of a raucous crowd at Levi's Stadium.

The 49ers' defense was brilliant in the win, and afterward, rookie defensive lineman Nick Bosa said the group took it to Baker Mayfield.

“I mean, I don't know how anybody thought he'd be able to see over Arik and Buck,” said Bosa, according to Tim Kawakami of The Athletic. “But he was panicking. He was double-clutching, rolling back and forth. We had him rattled all game.”

Bosa was a big part of that, as he logged four tackles and a couple of sacks in the win.

Mayfield had what was probably the worst game of his NFL career, completing just eight of his 22 passes for 100 yards and a couple of interceptions.

The miserable performance by Mayfield and the Browns came a week after it looked like they had made a breakthrough in a 40-25 road victory over the Baltimore Ravens.

Cleveland dropped to 2-3 on the season with the loss, and Mayfield's struggles after his terrific rookie campaign continued.

Thus far in his second year, Mayfield has thrown for 1,247 yards, four touchdowns and eight picks while completing just 55.9 percent of his passes and posting a passer rating of 68.5.

Bosa also took a shot at Mayfield on the field after the game, planting a 49ers flag in the end zone, much like Mayfield planted a Sooners flag at Ohio State's midfield following Oklahoma's road win over Bosa's Buckeyes back in 2017.