The Bills tied the game up early in the second quarter thanks to a 31-yard field goal by kicker Rian Lindell. Buffalo managed to shake off a sluggish first quarter start to get on the scoreboard, marching down the field on a 12-play, 75-yard drive.
But the 49ers responded less than a minute later, after Alex Smith connected on back-to-back passes to different wide receivers. Smith first hit Michael Crabtree on a 36-yard strike, and that set up a 43-yard touchdown pass to wide receiver/kick returner Kyle Williams.
San Francisco appeared to end the half on a sour note when backup quarterback Colin Kaepernick fumbled in the red zone. But Buffalo coughed the ball up just a few plays later, and San Francisco converted on a 28-yard touchdown to Crabtree.
San Francisco outgained Buffalo 320 to 123 in total yards. Alex Smith has been near perfect so far, completing 12 out of 15 attempts for 237 yards and two touchdowns. He also has a 24-yard run.