ST. LOUIS -- The 49ers gave up big plays on defense and gave up the ball on offense, but they got a huge boost from Colin Kaepernick and receiver Brandon Lloyd just before the half.
Stuck deep in their own territory after an ill-advised punt return by Bruce Ellington, Kaepernick looked up and found Lloyd streaking down the sideline after he had put a double move on cornerback Janorios Jenkins.
Lloyd, 33, caught Kaepernick's pass in stride and then outran Jenkins – eight years his junior -- for an 80-yard touchdown, the longest pass of Kaepernick's career. Lloyd had an 89-yard touchdown in 2005 during his first stint with the 49ers.
The score pumped some life into the 49ers in a half otherwise dominated by the home team.
The Rams came out aggressively early, hitting tight end Jared Cook on a 39-yard catch and run and, on one play, using diminutive wideout Tavon Austin in the backfield as a running back. Two 49ers penalties wiped out defensive stops, including a sack by Dan Skuta, and the Rams strung together an 11-play drive that ended with a short touchdown run by Benny Cunningham off of left tackle.
The 49ers, who were called for two penalties last week, have been flagged five times so far. One of them was declined.
Both the 49ers' offense and defense settled down on their second drives, with the 49ers forcing a Rams punt and Kaepernick hitting Anquan Boldin for a 20-yard gain.
The 49ers also had a well-designed play for tight end Vance McDonald, who played every snap last week but had no receptions. McDonald caught a short pass, then turned up field to find he had 20 yards of open space. But he lost the ball when he was hit by Rams free safety Rodney McLeod and the Rams took over at their own 45 yard line.
It didn't take them long to capitalize on the mistake.
Running back Tre Mason burst up the middle of the 49ers defense for 24 yards, the second longest run by an opposing tailback this year. Two plays later, cornerback Chris Culliver bit on a run fake, leaving tight end Lance Kendricks all alone in the end zone for an easy toss from quarterback Austin Davis and a quick 14-0 Rams lead.
One positive for the 49ers is that after going two straight games without a sack they had three on Davis in the first half with Ahmad Brooks, Skuta and Aaron Lynch each credited with one. Lynch's sack came on third down and forced a punt. It was the first of the rookie's career.
That led to the 49ers' first score of the game, a 54-yard field goal by Phil Dawson.
Read Matt Barrows’ blogs and archives at www.sacbee.com/sf49ers.