The San Francisco 49ers punched their ticket to the postseason as Ambry Thomas' overtime interception clinched a dramatic comeback win over the Los Angeles Rams.

San Francisco went into the Week 18 clash knowing a win would see them reach the playoffs for the second time in three seasons. A loss would allow the New Orleans Saints, who cruised past the Atlanta Falcons, to sneak in and claim the final Wild Card berth.

The latter outcome looked the more likely when the Rams surged to a 17-0 lead and, even though the Niners got a field goal before half-time, San Francisco still faced an uphill battle.

However, Deebo Samuel scored a touchdown on the ground and then threw another to Jauan Jennings on a trick play to tie things up.

A juggling interception of Jimmy Garoppolo by Jalen Ramsey in the endzone followed by a Matthew Stafford strike to Cooper Kupp put the Rams in a seemingly commanding position at 24-17.

However, Garoppolo - playing with a torn ligament in his right thumb - led a five-play, 88-yard drive that finished with him connecting with Jennings, forced overtime at SoFi Stadium.

The 49ers won the coin toss and a 12-play, 69-yard drive on which Jennings featured heavily set up a Robbie Gould field goal to give San Francisco the lead for the first time.

And it was an advantage they held as Stafford's deep shot for Odell Beckham Jr. was plucked out of the air by rookie cornerback Thomas to set up a mouth-watering Wild Card matchup with the Niners' historic rivals the Dallas Cowboys.

For Los Angeles, it is a sixth successive defeat to the 49ers, though they still won the NFC West after the Seattle Seahawks beat the Arizona Cardinals, whom the Rams will host in the opening round of the playoffs.