Sean Mannion completed 18 of 25 passes for 144 yards and led Los Angeles on two long second-half scoring drives as the Rams beat the Dallas Cowboys 13-10 Saturday at the Coliseum in Los Angeles.
Mannion, a third-year backup quarterback from Oregon State, took over for starter Jared Goff early in the second half and was effective while working deep into the fourth quarter.
However, Mannion wasn't able to drive the Rams for a touchdown, which Goff did in a short night's work.
Goff marched the Rams 33 yards for the game's first touchdown 4:01 into the game, the score coming when wide receiver Cooper Kupp fell on a fumble by teammate Robert Woods in the end zone.
The drive was set up when Cowboys punt returner Lance Lenoir fumbled a punt to set the Rams up at the Cowboys 33-yard line.
Goff went to work at the point, completing 3 of 4 passes for 34 yards, including a 19-yard strike to Kupp.
Kupp, a rookie from Eastern Washington, had two catches for 35 yards in his first NFL game.
Goff, who struggled last year as a rookie, looked good in his short stint that last just eight plays.
The Cowboys cut the lead to 10-3 on Dan Bailey's 32-yard field goal early in the second quarter.
That ended the first-half scoring, with the Rams moving ahead by a touchdown midway through the third quarter when Greg Zuerlein connected on 42-yard field goal.
The nine-play, 61-yard drive to put the Rams in field goal position was engineered by Mannion.
The Cowboys tied the game 10-10 when Cooper Rush connected with Rico Gathers on a 25-yard touchdown pass.
Rush completed 9 of 11 passes for 104 yards.
Travis Coons connected on a 36-yard field goal with 6:17 left in the fourth quarter to put the Rams back up 13-10
The third Rams quarterback to play Saturday, Dan Orlovsky, was 1 of 2 for 3 yards.
Rams running back Justin Davis was the game's leading rusher with 70 yards on nine carries, while Darren McFadden was the Cowboys' top rusher with 28 yards on six carries.