Los Angeles Rams wide receiver Tavon Austin, right, breaks away from San Francisco 49ers strong safety Eric Reid during the second half of an NFL football game Sunday, Dec. 31, 2017, in Los Angeles. (AP Photo/Rick Scuteri)

Rams head coach Sean McVay rested 17 starters and allowed quarterback Sean Mannion his first career start in their 43-13 loss against the San Francisco 49ers.

“We feel good about being able to allow some of our players to get some rest, a little bit of recovery time that I think is much needed for some of those guys and then you keep a couple guys out of harm’s way,” McVay said.

Mannion completed 20 of 34 passes for 169 yards, and running back Malcolm Brown made 14 carries for 54 yards. Wide receiver Michael Thomas had three catches for 75 yards and linebacker Cory Littleton made eight total tackles.

San Francisco quarterback Jimmy Garoppolo made 20 throws for 292 yards; tight end George Kittle grabbed four catches for 100 yards. Running back Carlos Hyde ran for 15 carries for 90 yards and linebacker Brock Coyle had eight tackles.

The 49ers had a strong rushing game, but incomplete passes would force them to kick a field goal. The Rams could not contain San Francisco on their next possession.

Wide receiver Marquise Goodwin received a touchdown pass, outrunning two Rams defenders on his way to the end zone.

The Rams defense made their mark when cornerback Kevin Peterson made a 38-yard interception play.   The Rams offense started on the San Francisco 22-yard line. Peterson picked off the 49ers twice on Sunday.

“They came in a formation that I recognized and we had a call that matched well to that formation and I just went and got it,” Peterson said. “I actually didn’t see it until the last second when I caught it, threw my hands up, prayed that I caught it and then I caught it and did what I had to do.”

A penalty by the 49ers pushed the Rams up to their eight-yard line. Mannion, however could not complete a pass. Special teams gave Los Angeles their first score 3-10.

49ers defenders bested the Rams throughout the first half. Los Angeles only earned one first down in the first quarter. San Francisco defensive lineman Cassius Marsh sacked Mannion. Goodwin and defensive back Blake Countess collided, sending both players out of the game with concussions.

San Francisco 49ers wide receiver Marquise Goodwin, left, scores past Los Angeles Rams middle linebacker Cory Littleton during the first half of an NFL football game Sunday, Dec. 31, 2017, in Los Angeles. (AP Photo/Mark J. Terrill)

To close out the first half, the Rams scored a field goal, edging their score to six.

San Francisco remained strong in the third period, limiting the Rams to two first downs. The passing game of Garoppolo was sound by then, sending the ball to wide receiver Kendrick Bourne for 16 yards and to tight end Garrett Celek for 28 yards to earn a first and goal.

The 49ers landed another touchdown by the hands of Hyde, edging their score up to 27. Cornerback Ahkello Witherspoon sacked Mannion, making a key turnover for San Francisco. Seven plays later, wideout Aldrick Robinson delivered a 12-yard touchdown passing play and the 49ers had 34 points.

The Rams continued to fight, as running back Lance Dunbar scored the only Los Angeles touchdown of the game midway through the fourth quarter, pushing the score up to 13.

The Rams will play the Atlanta Falcons on Saturday, January 6, at the L.A. Coliseum for the NFC Wild Card game. Despite the victory, the 49ers had been eliminated from playoff contention with a 6-10 overall record.

“I know we’re a playoff caliber team. We started off slow, we had that five-game stretch where we lost by three points or less,” said safety Eric Reid.  “I mean you have those five games and we’re in the playoffs probably. So, it’s tough. It’s a hard pill to swallow.”