Smith took a hard hit on the back of the neck from linebacker Jo-Lonn Dunbar after a scramble with 1:10 left in the first quarter. But the No. 1 overall pick in the 2005 draft stayed in and completed his next five passes, including Crabtree's TD.
After the hit, Smith was sacked three plays later and also clobbered again on a fourth-and-1 keeper. Doctors indicated to Harbaugh that might have been the play that caused the injury.
Harbaugh said Smith would be evaluated this week per NFL concussion protocol. He wasn't available to speak to reporters. Smith, who has started 28 straight games, wound up 7 for 8 for 72 yards.
The 49ers didn't face Bradford in either meeting last season as the Rams quarterback missed six games with a high left ankle sprain. He had all kinds of extra opportunities this time.
"It's a weird feeling. I've never been a part of a game like that before," Bradford said. "I think the mood in this locker room is disappointment."
Late in the third period, the Rams benefited from Dashon Goldson's 15-yard unsportsmanlike conduct penalty for taking off his helmet. Then, defensive tackle Ray McDonald was flagged for a helmet-to-helmet hit on Bradford when he came in under the quarterback's chin, extending another Rams drive. Zuerlein kicked a 27-yard field goal.
The penalties and miscues were uncharacteristic of San Francisco's defense.
Crabtree's touchdown midway through the second quarter gave him a TD reception in five straight games against the Rams. It was his third touchdown in two games, and all of his team-leading four TD catches have come in the past five games.
Kaepernick took over as Smith went to the bench to be examined by medical personnel and soon left for the locker room.
One wild play late in the first half summed up this wacky day. Punter Hekker completed a 21-yard pass to safety Rodney McLeod from the end zone after Chris Culliver didn't cover McLeod. Hekker did it again in the fourth quarter and had a 118.8 passer rating on the day.
On the Rams' 14-play, 81-yard drive over the final minutes of regulation, Hekker faked an end-around and threw a 19-yard completion to Kendricks on fourth-and-8 from the Rams 33.
But the Rams' defense couldn't get a stop, allowing Kaepernick to get his team back into field-goal range for Akers to tie it.
The Rams played without a pair of starters held out for an unspecified team rules violation, cornerback Janoris Jenkins and wide receiver Chris Givens — and Fisher said afterward he isn't sure if they will play next week at home against the New York Jets.
The 49ers will regroup to face the Bears in prime time.
"It feels weird," safety Donte Whitner said. "We're about wins around here."
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