The Los Angeles Rams have booked a second Super Bowl appearance in three years after staging a fourth rally to outmuscle the San Francisco 49ers 20-17.
Quarterback Matthew Stafford threw for two touchdowns while Matt Gay drilled a 30-yard field goal with 1:46 remaining to ensure the Rams will advance to the February 13 Super Bowl at their own SoFi Stadium.
The Rams will play Cincinnati in next month's NFL championship showcase after the Bengals upset the Kansas City Chiefs for the AFC title earlier on Sunday.
The nail biting NFC Championship showdown between the two Californian rivals effectively ended when 49ers quarterback Jimmy Garoppolo gave up an interception on San Francisco's final possession.
It was the final act of a tense duel at SoFi Stadium which had seen San Francisco's dogged defense lay the foundation for a 17-7 lead heading into the fourth quarter.
But Stafford found star receiver Cooper Kupp for his second touchdown of the game to make it 17-14 and then Gay nailed two field goals to give the Rams the lead.
There was still plenty of time for 49ers quarterback Garoppolo to launch a final drive for a possible game-winning score, but the Rams defense were in no mood to let the advantage slip.
Under pressure on 3rd & 13, Garoppolo desperately shoveled the ball away hoping to avoid a sack but instead it looped into the arms of Travin Howard to effectively end the game.
"That was an unbelievable performance by our team," Stafford said afterwards. "It didn't start the way we wanted it to, guys battled. I said in the locker room there's no way we're not going to win this damn game. Our guys put our minds to it and came out here and did it."
Stafford finished with 337 yards and two touchdowns, while Garoppolo finished with two touchdowns and 232 passing yards. (AFP)