About the only thing missing for San Francisco’s top-ranked defense this season was a shutout. The 49ers got that on Sunday and clinched their first playoff berth since 2002 with a 26-0 win over the visiting St. Louis Rams on Sunday.

San Francisco (10-2) wrapped up the NFC West title by limiting the Rams to just 31 yards on the ground and getting a pair of long touchdown passes from Alex Smith.

A.J. Feeley filled in for Sam Bradford (ankle) at quarterback for the Rams with no success. Feeley passed for 156 yards as St. Louis, losers of three straight, spent virtually the entire game in its own territory.

Stephen Jackson finished with 19 yards on carries and St. Louis (2-10) had just nine first downs in the game.

It was the sixth straight game that the Niners didn’t allow a touchdown in the first half, setting a franchise record. Buoyed by three David Akers field goals, they led 9-0.

San Francisco made it 16-0 early in the third quarter when Alex Smith connected with Michael Crabtree for a 52-yard touchdown.

Smith fired another long touchdown pass in the fourth quarter to Kyle Williams covering 56 yards. The two completions were the longest plays of the season for San Francisco.

Smith finished 17 of 23 for 274 yards before being removed in the fourth quarter.