WASHINGTON — NFL playoff top seeds Baltimore and San Francisco entertain bottom-seeded upstarts in this weekend's conference semi-final showdowns, providing a supreme test for clubs who have already toppled expected winners.

Run-pass quarterback threat Lamar Jackson leads the Baltimore Ravens, who had the NFL's best regular-season record at 14-2, against visiting Tennessee, which snuck into the final American Conference berth and dethroned New England last weekend on the road, in a Saturday matchup.

"I'm bringing a Super Bowl here. That's my goal," Jackson said. "I've been wanting a Super Bowl ever since I was a kid. That's why I play the game, because I want to win."

The National Conference top-seeded 49ers will host Minnesota, which won an over-time shocker at New Orleans, on Saturday while Sunday finds Seattle at Green Bay in the National Conference and Houston at Kansas City in the American.

Wins by the Ravens and 49ers would make them hosts for the Jan. 19 conference championship games that determine the rivals in Super Bowl 54 on Feb. 2 at Miami.

This week's home teams, who enjoyed first-round byes, are 16-4 over the past five seasons at this stage of the NFL playoffs and no team that played in the opening round has reached a Super Bowl since the 2012 season.

Jackson set an NFL quarterback rushing record of 1,206 yards, leading the NFL with 36 touchdown throws while guiding the league's top-scoring attack. His title hunger has sparked the Ravens.

"It's infectious. I haven't seen anyone that's so hell bent on winning. It's all he cares about," said Ravens tight end Mark Andrews, who caught a team-high 64 passes for 852 yards and 10 touchdowns.

"When he says the only thing he cares about is winning a Super Bowl, he means that. He has been saying that since Day One and that has rubbed off on everyone in this locker room."

Baltimore rusher Mark Ingram, who played a key role in the Ravens becoming the greatest rushing attack in NFL history, practiced Thursday for the first time since suffering a calf injury last month.

Tennessee counters with running back Derrick Henry, the NFL's season rushing leader with 1,540 yards, and a solid defensive unit that blanked Tom Brady in the second half of the Titans' stunner over the Patriots.

The 49ers, who missed the playoffs the past five seasons, are five-time Super Bowl champions, the most recent in 1995, while the Vikings have lost all four trips to the title game, most recently in 1977.

San Francisco quarterback Jimmy Garoppolo, twice a Super Bowl winner as a Brady backup in New England, makes his first playoff start guiding a versatile attack that features rookie receiver Deebo Samuel, tight end George Kittle and veteran receiver Emmanuel Sanders.

The Vikings counter with rusher Dalvin Cook but receiver Adam Thielen is questionable with an ankle injury.

Green Bay matched the NFL's best home win mark with seven victories at Lambeau Field, but will face a Seahawks squad that is 8-1 on the road, including a playoff win at Philadelphia last weekend.

"We've been road warriors and it's exciting," Seattle quarterback Russell Wilson said.

Packers quarterback Aaron Rodgers, who guided Green Bay to a 2011 Super Bowl triumph, yearns for a second NFL crown at age 36.

"It's on my mind every day. That's why we play the game," Rodgers said. "That's why you put in the time in the off-season.

"I know what this is all about. This is an important opportunity for us... I want to make the most of this opportunity."

Houston won 31-24 at Kansas City earlier this season, the Texans rallying after the Chiefs seized a 17-3 lead. Kansas City was missing five starters and quarterback Patrick Mahomes was slowed by a sore ankle, but the Chiefs defenders could not sack Texans quarterback Deshaun Watson.

Watson converted a fourth down to run down the clock in that game, but Mahomes was no pushover. The Chiefs star threw for 273 yards and three touchdowns.

"It's a wonderful feeling to deal with all of the adversity, the ups and downs and the flows of the game, and keep fighting for 60 minutes," Watson said. "We never got discouraged. We kept fighting." — AFP