LOS ANGELES (AFP) — The injury-hit San Francisco 49ers sent the reigning Super Bowl champion Philadelphia Eagles crashing out of the National Football League playoffs on Sunday in a stunning wild card round upset.

Niners running back Christian McCaffrey scored two fourth-quarter touchdowns and San Francisco's depleted defense shut down Philadelphia's offense to complete a famous 23-19 road win at Lincoln Financial Field.

The 49ers — who have been decimated by a deepening injury crisis that has robbed them of key personnel for much of the season — suffered yet another cruel injury blow in the second quarter when tight end George Kittle hobbled off with an Achilles injury.

Yet Niners quarterback Brock Purdy and the dynamic McCaffrey shrugged off that latest injury setback to inspire a victory that sets up a divisional-round clash with the top-seeded Seattle Seahawks next weekend.

"Our team just fights," 49ers touchdown hero McCaffrey said afterwards. 

"We knew it was going to be a 12-round fight, and we just had to stick with it no matter what happened during the game, good or bad.” 

"We just kept trusting each other and we ended up winning."

Purdy tossed two touchdowns and finished with 262 passing yards. 

But the pick of the Niners touchdowns came early in the fourth quarter, when a cleverly designed trick play ended with Jauan Jennings launching a 29-yard touchdown which helped San Francisco into a 17-16 lead.

Although Philadelphia regained a slender 19-17 lead with a 41-yard Jake Elliott field goal, the unflappable Purdy produced another ice-cold drive to move the ball 66 yards before connecting with McCaffrey in the end zone for the winning score.

San Francisco's win means the Los Angeles Rams will travel to Soldier Field next week to face the Chicago Bears in the other NFC divisional playoff game.

In the AFC, meanwhile, Josh Allen rushed for a game-winning touchdown as the Buffalo Bills outdueled the Jacksonville Jaguars 27-24 in a roller-coaster wild card thriller.

Bills quarterback Allen was once again the hero for Buffalo, almost single-handedly dragging his team over the line against the in-form Jaguars side led by Trevor Lawrence.

Allen rushed for two touchdowns and threw one more while finishing with 273 passing yards from 28-of-35 attempts, with no interceptions.

A hectic fourth quarter saw the lead change hands four times before Allen led a late 66-yard touchdown drive which included a crucial fourth-down conversion from the Jacksonville 11-yard line that carried the Bills to the brink of the end zone.

Allen then barged his way over to give sixth-seeded Buffalo a 27-24 lead after Matt Prater's extra point, leaving third seeds Jacksonville with barely a minute to find a game-tying field goal.

Disaster struck, though, on the opening play of the Jaguars' final drive, with Lawrence tossing an interception to effectively end the game.

"Great game, great win," Allen said afterwards. 

"All we've got to do is play our game, find a way to win a football game and we're on to the next one.”

"We're going to play for each other, we're going to fight to the very last second and you saw that here today." 

The identity of Buffalo's opponents in the next playoff round will hinge on the outcome of other AFC wild card games being played on Sunday and Monday.