Backup quarterback Colin Kaepernick, who ran for 39 yards on four carries, fumbled on an end-around and Buffalo took over at its own 17. Two plays later, Patrick Willis stripped Scott Chandler, San Francisco recovered and Smith floated a 28-yard touchdown to Crabtree to put the 49ers in front 17-3 with 24 seconds to go before the half.
‘‘Everything about today was just amazing,’’ Crabtree said.
A holding penalty on Buffalo’s Jairus Byrd wiped out a punt return Leodis McKelvin took for a touchdown in the first quarter. The offense failed to score any points after McKelvin returned a kickoff 59 yards. And after a 12-play, 75-yard drive that took nearly 6 minutes stalled in the second quarter, Lindell kicked a field goal for Buffalo’s only score.
Smith led another touchdown drive that featured Kaepernick gaining 15 yards on a sweep and ended one play later when Gore dove over the pile for a TD that extended San Francisco’s lead to 24-3.
Chris Culliver intercepted an underthrown pass by Fitzpatrick just shy of the goal line to end Buffalo’s best chance to reach the end zone all afternoon.
Smith also tossed a 10-yard TD pass to Mario Manningham, Kaepernick ran 16 yards for a score and Anthony Dixon added a 3-yard run for the final touchdown.
‘‘I'm not a big statistical guy, don’t get caught up in it,’’ 49ers offensive coordinator Greg Roman said. ‘‘But at the same time, just in the normal course of events to be able to throw up that kind of production, obviously we’re doing something right.’’
NOTES: Buffalo allowed 500 yards in consecutive games for the first time in franchise history. ... Bills DE Mario Williams wore a small stabilizer on his left wrist instead of the brace he had the first four weeks. He appeared to grimace after a few plays. ‘‘It’s good one day, and bad the next day,’’ said Williams, who had two tackles and no sacks. ... Byrd injured a chest muscle, and Bills OL Chad Rinehart hurt his calf in the second half and did not return. Both are day to day.
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