San Francisco secured a bye-week in the playoffs with Sunday's win in St. Louis.
The 49ers beat the Rams 34-27.
The NFC-worst Rams made a game of it, but in the end the 49ers swept the season series for the third year in a row.
Even before the kick-off the 49ers had already clinched the NFC title and their first playoff berth since 2002. The bi-week means the fans will have one less playoff game to watch.
On Sunday, San Francisco was without two wide receivers for the regular season finale, with wide receiver and return man Ted Ginn Jr. sidelined by an ankle injury and Kyle Williams out with a concussion.
Neither practiced all week. Brett Swain, who entered Sunday's game against the St. Louis Rams with one reception, starts for Ginn. Wide receiver Joe Hastings was promoted from the practice squad.
Michael Crabtree caught two touchdown passes. One of them came on the throw of kicker David Akers on a perfectly executed trick play.
Crabtree and Vernon Davis had big days for a team short of pass catchers and Tarell Brown had a pair of interceptions that led to touchdowns as the 49ers (13-3) beat the Rams (2-14) for the second time the last five games.
The 49ers held St. Louis to just 157 total yards in a 26-0 victory that clinched the NFC West in Week 12 but were hanging on at the finish of the rematch after the Rams scored two touchdowns in just 13 seconds late in the fourth quarter to cut the deficit to seven points.