WASHINGTON (AFP) — Denver grabbed a National Football League (NFL) playoff top seed, Carolina backed into a first playoff berth since 2017 and Pittsburgh captured a winner-take-all showdown to reach the post-season on a hectic final Sunday of the campaign.

The Denver Broncos took the AFC top seed, a first-round bye and a home-field playoff edge with a 19-3 victory over the visiting Los Angeles Chargers.

"We understood what was at stake and now we sit here with the... one seed, which is pretty good," Broncos coach Sean Payton said.

The Broncos (14-3) have not been a top seed since 2015, the Super Bowl-winning season they last won a playoff game.

Next week's AFC playoff openers find the Chargers at New England, Buffalo at Jacksonville and Houston at Pittsburgh, which beat Baltimore 26-24 for the AFC North division crown and final playoff spot.

In a fourth-quarter see-saw drama, Baltimore's Lamar Jackson hit Zay Flowers with touchdown passes of 50 and 64 yards while Kenneth Gainwell had a two-yard touchdown run and 42-year-old quarterback Aaron Rodgers threw a 26-yard touchdown pass to Calvin Austin with 55 seconds remaining, but Chris Boswell missed the extra point, creating the final margin.

Baltimore's Tyler Loop missed a 44-yard field goal attempt wide right on the last play to hand Pittsburgh the nerve-wracking victory.

"When we had to have points, we went down and scored," Rodgers said. "It's pretty emotional.”

"We found that something special, which is belief, and I'm proud of our guys the way we responded in the fourth quarter."

Steelers linebacker T.J. Watt made two tackles in returning from a collapsed lung.

"It truly was awesome," Watt said. "Just tried to fly around and feed off the energy."

In the NFC, Seattle took the top seed Saturday by beating San Francisco 13-3. NFC openers will find Green Bay at Chicago, the Los Angeles Rams at Carolina and San Francisco at defending champion Philadelphia.

The Carolina Panthers, who lost 16-14 to Tampa Bay on Saturday, took the final NFC playoff spot when the Atlanta Falcons beat New Orleans 19-17 on Sunday.

Carolina and Tampa Bay were 8-9 and after the triumphant Falcons matched them, the NFC South title and playoff berth came down to a head-to-head results tie-breaker won by the Panthers.

"Proud of everybody," Panthers coach Dave Canales said. "We're ready to chase the next championship opportunity in front of us."

Carolina's next foe, the Rams (12-5), got four touchdown passes from Matthew Stafford in a 37-20 home triumph over Arizona. The Rams lost 31-28 at Carolina in November.

"They're a pretty talented team," Stafford said. 

"They're playing well enough to be in the dance so we have our work cut out for us."

Despite Atlanta's victory, the Falcons fired coach Raheem Morris after a two-season record of 16-18.

The Chargers (11-6) visit a 14-3 Patriots team that routed Miami 38-10 as Rhamondre Stevenson and TreVeyon Henderson each ran for two touchdowns.

Jacksonville's Trevor Lawrence threw for 255 yards and three touchdowns in a 41-7 rout of Tennessee, stretching the Jaguars' win streak to eight games.