The Cincinnati Bengals have a young, unproven offense and a fan base that had pored over All-22 film breakdowns long enough to demand the team draft an offensive lineman last April to shore up its future. Riding high off a Week 16 win over the Baltimore Ravens, the Bengals figured that facing Patrick Mahomes and a savvy Kansas City Chiefs team on Sunday would remind them how much growing they would need to reach the A.F.C.’s golden standard.

In a 34-31 upset, the Bengals (10-6) proved that choosing wide receiver Ja’Marr Chase in the 2021 N.F.L. draft was the gap closer the team needed.

The Bengals locked up their first A.F.C. North title since 2015, and made one fact very clear:

Joe Burrow throwing deep to Ja’Marr Chase is the N.F.L.’s most dangerous connection.

Again and again, with ruthless precision, the former Louisiana State teammates Joe Burrow and Ja’Marr Chase tore up a Kansas City defense that had been shutting down just about every team it had faced in the past two months. Burrow completed 11 passes on 12 targets to Chase for three touchdowns and 266 receiving yards.

Two of those game-swinging shots came on the winning field-goal drive. With the score tied, 31-31, and 4 minutes 21 seconds remaining, Burrow first unloaded a 35-yard pass deep right to Chase, who was being suffocated by cornerback Charvarius Ward. After a holding penalty and a sack marred the next two plays, the Bengals faced a third-and-27 from Kansas City’s 41-yard line.

Cincinnati appeared to call the same exact play, having Burrow simply chuck it deep to Chase, who hauled it in for 30 yards, again over Ward. So anticipated was the target that Burrow said afterward, “Everyone knows that meme,” adding in explanation: “Ja’Marr’s down there somewhere.”

From there, the Bengals were able to melt time off the clock, and an illegal use of the hands penalty on L’Jarius Sneed on fourth-and-goal from the 1-yard line allowed the Bengals to drain even more. Evan McPherson kicked the game-winning 20-yard field goal with no time left.

The comeback win, in which Kansas City had led by as many as 14 points, showed Cincinnati is as powerful a contender as any of the A.F.C.’s more respected franchises.

Mahomes has looked typically dangerous in recent weeks, fitting throws in against defenses that prop two safeties deep and cutting back on the blooper-reel interceptions.

Josh Allen has mostly carried the third-rated offense of the Buffalo Bills’ (10-6) on his back this season. Running back Jonathan Taylor of the Indianapolis Colts (9-7) will wrap up his rushing title next week. The Tennessee Titans (11-5) expect to welcome back Derrick Henry soon.

Yet after Week 17, this Burrow-to-Chase connection is most responsible for morphing a team that went 2-14 in 2019 into title contenders in 2021. Drafting Chase with the fifth pick over left tackle Penei Sewell, who went seventh, to Detroit, has proved a franchise-altering decision.

Burrow was beat up a ton as a rookie, resulting in a major knee injury that ended his 2020 season. He has been sacked 47 times this season, behind a line that was built through free agency. But Burrow can quickly hit Chase for 30 or more yards, exquisitely placing deep shots where he knows his former college teammate can grab them.

And Burrow knows Chase can turn his less perfect throws into gains.

With the Bengals trailing, 14-0, late in the first quarter on Sunday, Chase caught a short pass and should have been blasted by linebacker Nick Bolton. Instead, Chase, a 6-foot, 201-pound receiver, hit the brakes to completely evade Bolton and then outraced the Kansas City defense to the end zone for a 72-yard score. Safety Juan Thornhill, who once ran a 4.42 in the 40-yard dash at the N.F.L. combine, appeared to have a perfect angle covering over the top, and Chase still dusted him.

With Kansas City threatening a blowout, Chase boxed out Ward for his second touchdown grab to pull the Bengals within 7 points midway through the second quarter. When Ward threw his hands up in disbelief, he might as well have waved a white flag.

There is likely nothing Ward or Darrelle Revis or Deion Sanders or anyone else could’ve done against Chase one-on-one Sunday. If any A.F.C. teams hope to beat Cincinnati in the postseason, they will probably have to bracket a safety over the top.

Burrow has 971 passing yards, eight touchdowns and no interceptions in his last two games. One week ago, when Don Martindale, the defensive coordinator of the Baltimore Ravens, said he wouldn’t use his depleted secondary to double- or triple-team Chase because “I don’t think we’re ready to buy a gold jacket for Joe,” Burrow made him eat his words. On Sunday, he did it against a Kansas City defense that hasn’t been lit up since September.

Of course, the scariest part of all this is that Burrow is 25 years old and Chase is 21.

The Buccaneers will need everything Tom Brady can give.

First, the New Orleans Saints beat them in a Week 15 shutout. The Tampa Bay Buccaneers didn’t lose only that game at home: Wide receiver Chris Godwin tore an anterior cruciate ligament and running back Leonard Fournette injured a hamstring.

On Sunday, it sure appeared the lowly Jets (4-12) would deliver to Tom Brady one of his most embarrassing losses in his 22 pro seasons.

Not only did the Jets build a 14-point lead, but Antonio Brown, the receiver whom Brady lobbied the team to acquire in free agency in 2020, unexpectedly stormed off the field in the third quarter.

Brady wound up saving a 28-24 win with a nine-play, 93-yard touchdown drive in the game’s final minutes. On the scoring pass, he threw a 33-yard touchdown laser to Cyril Grayson: The pass was so forceful its momentum nearly carried Grayson the two steps into the end zone.

But the Buccaneers’ foundation appears cratered at the worst possible moment. Afterward, Coach Bruce Arians indicated Brown would be released from the team. With Godwin’s season-ending tear and major injuries to Shaq Barrett and Jason Pierre-Paul denting the Buccaneers’ vaunted pass rush, the onus of Tampa Bay’s postseason hopes will rest on Brady elevating the likes of Grayson and Tyler Johnson to augment his options beyond Rob Gronkowski and Mike Evans.

At this point a year ago, Tampa Bay, healthy and peaking, blasted the Detroit Lions by 40 points. Now, despite Sunday’s win, Brady and the Buccaneers have a much different road to a title repeat.

Around the N.F.L.

Eagles 20, Washington Football Team 16: It was easy to mock Eagles Coach Nick Sirianni in the spring when he said he had played rock paper scissors with draft prospects to gauge their competitiveness. Nobody’s mocking him anymore. After a 2-5 start, Sirianni pivoted Philadelphia to rely more on the run and now, at 9-7, Philadelphia is on the verge of making the playoffs. Cornerback Rodney McLeod supplied the game-sealing interception of Taylor Heinicke in the end zone.

Rams 20, Ravens 19: This win showed why the Rams traded for Odell Beckham Jr. On fourth-and-5 from the Ravens’ 12-yard line, with 1:08 left, Beckham hauled in an extremely difficult 5-yard reception. Matthew Stafford, who had been intercepted twice on Sunday, went back to the receiver for a 7-yard touchdown pass on the next play.

Bills 29, Falcons 15: Josh Allen’s three interceptions gave the Bills a scare but the re-emergence of running back Devin Singletary helped push Buffalo to the win. Last season, the Bills showed zero desire to run the ball in January, even calling 20 consecutive pass plays to open up the divisional playoff game against Baltimore. With so many opposing defenses focused on stopping Allen, Singletary, who shredded the Falcons for 110 yards and two touchdowns on 23 carries, could provide much-needed balance.

Patriots 50, Jaguars 10: The rookie quarterback Mac Jones got back on track by going 22 of 30 for 227 yards with three touchdowns and no interceptions. Of course, in New England, it all starts with the run. Damien Harris and Rhamondre Stevenson, who combined for 142 yards, helped create opportunities for Jones to throw successfully.

Raiders 23, Colts 20: Receiver Hunter Renfrow made the play of the game, selling out for a 24-yard reception on third-and-10 with 54 seconds left to set up a game-winning field goal.

Titans 34, Dolphins 3: So much for the Dolphins’ valiant playoff run. Their seven-game win streak came to a screeching halt in Nashville as Mike Vrabel’s team relentlessly leaned on the run for 198 yards on 40 attempts, even without Derrick Henry. The Titans are one win away from locking up the No. 1 seed in the A.F.C. for the playoffs.

Bears 29, Giants 3: John Mara, a Giants co-owner, may indeed want to stick with Coach Joe Judge beyond this season, but after yet another uninspiring effort — in which Mike Glennon completed four passes with two interceptions and was sacked four times — Mara was again confronted by a team whose problems run deeper than any one player, coach or general manager.