The Ravens (10-6) had already clinched their second straight AFC North title, putting them in line to host Andrew Luck and the Indianapolis Colts next weekend.
The Bengals (10-6) were locked into the sixth seed as the final wild-card team. The only question was who they would play in the opening round, and that wouldn't be answered until games were completed.
So, they went into preseason mode on a 26-degree afternoon with a wind chill of 16.
Josh Brown kicked three field goals in the second half. Dunlap tipped one of Tyrod Taylor 's passes to himself and returned it for a clinching touchdown with 6:06 left, jumping into the stands and sitting there for several seconds while fans smacked his back.
The Bengals headed into the playoffs for the second straight season after beating rivals Pittsburgh and Baltimore in back-to-back weeks.
They'd been 0-6 against them over the past two seasons, so a strong finish represented a breakthrough, even though the win on Sunday resembled more of an exhibition than anything.
The Ravens sat some of their banged-up playmakers and pulled Flacco and running back Ray Rice after the second series. Receiver Anquan Boldin , defensive tackle Haloti Ngata and linebacker Terrell Suggs were inactive, giving them a week to rest.
The Bengals were trying to get their running game into postseason shape after it managed only 14 yards during a 13-10 win in Pittsburgh a week earlier.
Running back BenJarvus Green-Ellis pulled a hamstring during pregame warm-ups and didn't play.
The Bengals went with a conservative approach. Dalton didn't even throw toward A.J. Green until the final drive of the first half, keeping the Pro Bowl receiver out of harm's way.
He finally found him for a 17-yard gain that set up an 11-yard touchdown pass to Marvin Jones , tying the game at 7 heading into halftime.
That was the offense's only touchdown in the last two games.
Bruce Gradkowski took over in the second half for Dalton, who was 10 of 15 for 78 yards with a pair of sacks. Green and others spent the second half on the bench as well.
Brown kicked field goals of 47, 32 and 38 yards in the second half. Brown will be the Bengals' kicker in the playoffs with Mike Nugent sidelined by a calf injury. Brown is 11 for 12 on field goal tries since he signed as a free agent, the only miss on a 56-yard attempt in Pittsburgh.
Taylor, who had thrown only four passes all season, replaced Flacco in the first quarter and led a pair of touchdown drives by running away from defenders. He had a 28-yard scramble and a pitch to Anthony Allen on an option play that went for 20 more yards. Allen then ran the final 2 yards for the score.
Taylor also scored on a 1-yard run in the second half.