The San Francisco 49ers stay unbeaten, moving to 5-0 on the season, after their defense dominated the Los Angeles Rams in a 20-7 road win over their NFC West divisional rivals.
The Rams scored on their opening possession of the game, Robert Woods running in for eight-yard touchdown, but were held scoreless thereafter as the 49ers racked up 20 unanswered points.
San Francisco's stellar defense was the key to their victory - they held the Rams to just 165 total yards, sacked Jared Goff four times, forced a fumble, produced a crucial goal-line stand late in the first half and forced L.A. to turnover on downs three more times in the fourth quarter.
The game was tied at 7-7 at half-time, with San Francisco suffering their own miscues on offense - Jimmy Garoppolo throwing an interception down near the goal line and Robbie Gould missing a fourth-straight field goal - but they romped clear in the second half.
L.A. returned all of minus 12 yards on offense in the third quarter, while Garoppolo atoned for his earlier error by running in a one-yard touchdown following a Rams fumble on the opening play from scrimmage of the second half.
Gould too finally found his kicking boots, firing through 25 and 34-yard chip shots to stretch San Francisco's lead, one which their ferocious defense determinedly clung on to.
That narrative had looked unlikely early in the contest as Woods capped an impressive all-run, seven-play, 56-yard drive with a touchdown - the first rushing touchdown San Francisco's stout defense have conceded all year.
The Niners responded with a fine drive of their own, tying things up with a two-yard Tevin Coleman score. The drive had almost ended in the same way San Francisco's first did, with a quarterback sack, but an offside penalty on Dante Folwer negated that play and Jimmy G then found George Kittle to keep the chains moving.
On their next possession, Garoppolo again found Kittle for a 45-yard pass play - their longest of the season - but he was then intercepted by Marcus Peters in the endzone when looking for his tight end again.
The Rams continued to struggle on offense but, having pinned the 49ers inside their own 10-yard line after punting, they earned great field position when forcing a three and out.
Darrell Henderson broke out a big 22-yard run and suddenly L.A. looked primed for the go-ahead score, only for the 49ers defense to shut them down at the one-yard line - back-to-back Malcolm Brown runs on third and fourth down stuffed.
Into the final three minutes of the first half, the 49ers were able to convert on their own fourth-and-one try, helping set up a Gould 55-yard field goal try as time expired, but he followed up his three misses in last week's win over the Cleveland Browns with another.
The Rams got off to the worst possible start to the second half, with Henderson failing to reel in Goff's pitch and fumbling on the first play from scrimmage, setting up Garoppolo's rushing score at the goal line.
L.A. looked like they had caught a break when punting following another three and out on offense. The Rams recovered after an accidental ricochet of a 49ers player, but the play was called back for an 'illegal motion' penalty on Mike Thomas.
San Francisco couldn't find much more on offense for the remainder of the contest, but didn't need to. A conservative approach, leaning on the run game, helped tee up two Gould field goals to stretch the lead to 13.
Aaron Donald did force a strip sack of Garoppolo in the fourth quarter, but the Rams' failure to move the football against San Francisco's swarming defense continued right up till the final whistle.
What's next?
The Rams head out on a three-week road trip, starting at the Atlanta Falcons and finishing at the Pittsburgh Steelers. Sandwiched in between is their London 'home' game against the Cincinnati Bengals at Wembley in Week Eight.
The 49ers travel east to Washington to take on the Redskins, who registered their first win of the season on Sunday by besting the still winless Miami Dolphins. San Francisco return home to host the Carolina Panthers in Week Eight.