SANTA CLARA, Calif. (AP) - Colin Kaepernick struggled and fumbled away the potential winning score for the 49ers, while the Rams and former third stringer Austin Davis beat another NFC West power Sunday.
St. Louis (3-5) remains in last-place, but the Rams have had plenty to say about the division race, upsetting Seattle and San Francisco in the past three weeks. They held on to beat the 49ers 13-10 Sunday when Kaepernick fumbled on a quarterback sneak at the goal line with 2 seconds left.
It was one of Kaepernick's worst home games, and came just three weeks after he had a winning performance in a 31-17 victory in St. Louis. On Sunday, the Rams sacked him eight times.
Despite his struggles, Kaepernick appeared headed in for the winning score after a drive that started with 3:11 left on the 49ers' 12. He completed long passes to Stevie Johnson and Anquan Boldin, then Trumaine Johnson helped the 49ers get closer with back-to-back pass interference and holding penalties as he defended Michael Crabtree.
Kaepernick tried a quarterback sneak from the 1 on third and goal, bobbled the snap and then fumbled as he went down short of the goal line. James Laurinaitis recovered for the Rams.
The play was reviewed and upheld. If Kaepernick had maintained possession, the 49ers could have used their final timeout to try for the touchdown again, or attempt a field goal to tie.
Greg Zuerlein kicked the go-ahead 39-yard field goal for the Rams (3-5) with 5:25 left.
The Rams, 9 1/2-point underdogs to start the week, never let Kaepernick get comfortable. Kaepernick spent more time on his backside and running from St. Louis defenders than he did smoothly directing the offense.
Playing for the second time in 21 days, the teams both were coming off embarrassing routs - the Rams last week 34-7 in Kansas City and the 49ers 42-17 at Denver on Oct. 19 - and this wasn't pretty, either.
The Niners did little to impress with World Series champion San Francisco Giants Brian Sabean, Bruce Bochy, Pablo Sandoval and Brandon Crawford, in the stands wearing 49ers gear. Former coach George Seifert was in attendance as well to be honored for his induction into the franchise Hall of Fame.
Kenny Britt caught a 21-yard touchdown pass that tied the game at 10 1:04 before halftime. Britt was wide open on a crossing route and easily ran in down the left sideline. That came three plays after the Rams capitalized on Robert Quinn's sack that forced Kaepernick into losing his first fumble of the day.
Then, the crazy final play of the first half was upheld on replay review.
When Phil Dawson's 55-yard field goal try came up well short on the final play of the half, Tavon Austin caught the ball near the back of the end zone and brought it out a few yards before backtracking to try to get around the right edge.
Derek Carrier tackled Austin in the end zone as the first-half clock expired.
As the two teams headed for their respective locker rooms, the head coaches stayed put for the ruling - which was that forward progress was stopped in the field of play and the play stood without a safety.
Kaepernick threw an earlier 27-yard catch to Boldin, giving him TD passes in 15 straight games - tied for the second-longest streak in franchise history with Jeff Garcia. Hall of Famer Steve Young had 17 in a row.
The Rams had six sacks total in their first seven games before doubling that total in the first half.
Quinn had two of St. Louis' five second-quarter sacks and five sacks in his last three games, with four and two forced fumbles in his last two.
When the NFC West rivals first played Oct. 13, Kaepernick threw for 343 yards and three touchdowns with no interceptions or sacks.
Rams quarterback Austin Davis had a scare in the first quarter. After a 10-yard scramble up the middle, he slid on his braced left knee and it caught awkwardly in the loose sod that has been problematic at $1.3 billion Levi's Stadium. Backup Shaun Hill entered for one play and Davis returned.
San Francisco struggled to get pressure on Davis, while missing star linebacker Patrick Willis missing his second straight game with an injured left big toe. San Francisco sacked Davis five times in the 31-17 win last month.
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