SANTA CLARA, Calif. -- The Cleveland Browns were humiliated, humbled and, ultimately, hammered on Monday Night Football in a wholly hapless showing. The San Francisco 49ers rolled 31-3, effectively putting the Browns away on the first series of the second half with an appropriately overpowering 90-yard touchdown drive.

Last Sunday, it seemed that the Browns had finally turned a corner following an impressive victory over AFC North rival Baltimore. Instead, Cleveland returned to looking completely discombobulated on Monday, with a series of bumbling miscues.

During their infamous 0-16 season in 2017, the Browns trailed by 25 or more points only twice. Already this season, they’ve lost by a greater margin than that on two occasions.

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San Francisco pass-rusher Nick Bosa added insult to the annihilation just before halftime. After driving Browns quarterback Baker Mayfield into the turf yet again to force an intentional grounding, he popped up and mimicked waving a flag, then planting it, with Mayfield flat on the ground behind him. The celebration was retaliation for Mayfield planting the Oklahoma flag in Ohio Stadium two years ago after a Sooners victory over Bosa and the Ohio State Buckeyes.

Bosa made sure Mayfield would have nothing to celebrate this time around. The No. 2 overall draft pick finished with two sacks, five quarterback hurries, a forced fumble and a fumble recovery, reducing Cleveland's star-studded offense to a shell of its former hyped self.

Pivotal play: For all their struggles, the Browns were very much in the game midway through the second quarter, with a chance to trim the deficit to 14-10. But Mayfield's would-be touchdown pass to a wide-open Antonio Callaway bounced twice off Callaway's hands as he slid into the end zone, and the ball fell into the arms of K'Waun Williams, who returned the pick 49 yards the other way. Six plays later, San Francisco scored another touchdown to go up 21-3, putting Cleveland on its heels for the rest of the night.

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Troubling trend: Cleveland had no answer up front for San Francisco's talented and swarming defensive line, which harassed Mayfield throughout the night. On the Browns' second possession, Bosa bulled his way past tight end Demetrius Harris and forced Mayfield into an ill-advised interception. In two of Cleveland's three losses, pass protection has been the downfall. Unless general manager John Dorsey can pull off a trade (Trent Williams, anyone?) it’s difficult to see how this will get any better.

QB Breakdown: Although he didn't get a lot of help from his line or his receivers, this wasn't a pretty performance for Mayfield. He started 0-for-4 passing for the first time in his career. He became the first NFL QB since 2008 to go through the first four drives of a game with zero completions and two turnovers. And with two more picks Monday, he leads the NFL with eight interceptions. The Browns have to be better in other areas, but Cleveland isn't going anywhere unless Mayfield plays a lot better.