SAN FRANCISCO -- Outside linebacker Aldon Smith took over sole possession of the 49ers' single-season sack record on Sunday.
Smith ran over Miami Dolphins rookie left tackle Jonathan Martin to pick up sack No. 18.5 of the season. Smith previously shared the 49ers franchise record of 17.5 sacks with Hall of Famer Fred Dean (1983).
Smith leads the NFL in sacks. He is four sacks behind Michael Strahan for the NFL single-season record, which Strahan set in 2001.
With 32.5 sacks in his first two seasons, Smith has more sacks in his first two seasons than any player since the NFL began keeping sack statistics in 1982.
Smith overpowered Martin, making his first start for All-Pro left tackle Jake Long, who is out for the season with a torn triceps. Martin started every game this season at right tackle. The sack forced the Dolphins to settle for a short field goal. The Dolphins led 3-0 early in the second quarter.