SANTA CLARA, Calif. _ One snap in, Matt Breida was gone on an 83-yard, lightning-quick touchdown run.
Four games in, the 49ers are undefeated, rocketing out of their 2014-18 funk and into the NFC driver's seat with 12 long but enticing games to go.
Monday night's 28-3 rout of the Cleveland Browns showed how deadly their rushing attack is (275 yards), how dominant their defense has become (4 sacks, 4 takeaways), how wily coach Kyle Shanahan and his staff can be, and how healthy quarterback Jimmy Garoppolo looks in his and the 49ers franchise's comeback season.
The 49ers, 4-0 for the first time since 1990, have their first NFC West test awaiting them Sunday, when they visit the suddenly vulnerable Rams (3-2) at the Los Angeles Memorial Coliseum, which has featured bipartisan crowd support the past three visits.
The Browns (2-3) proved no match from the outset, starting with Breida's 83-yard touchdown that clocked at a NFL season best 22.3 mph.
The only drawback of the 49ers' rushing showcase: Pro Bowl fullback Kyle Juszczyk got hurt with 3:04 left in the third quarter. He's been a major reason for the 49ers' dominance with lead blocks, as was the case Monday to assist Breida (114 yards, 11 carries) and Coleman (97 yards, 16 carries).
Rookie defensive end Nick Bosa led the defense's coming-out party, producing two sacks, a forced fumble, a fumble recovery, four quarterback hits and so much more against Baker Mayfield, Odell Beckham Jr., Nick Chubb and other Browns who got neutralized.
By halftime, the 49ers racked up 185 rushing yards, the final 19 of which came on Tevin Coleman's first touchdown of the season for the 21-3 lead. Breida's 5-yard touchdown catch made it 14-0.
Here are the studs and duds from first-half action:
