After carrying confidence and momentum into the regular season finale, Carolina found itself outplayed, out-coached and, yes, outsmarted by a Duke team that now calls itself ACC Coastal Division champion.

How could that happen when almost everything (including a 5.5 point spread) seemed to favor the Tar Heels at home on Senior Day before a capacity crowd that mostly arrived on time after causing a massive traffic jam surrounding Kenan Stadium?

Well, the 10-2 Blue Devils made one mistake all of the sunny, brisk day under clear Carolina Blue skies, a muffed punt by their star Jamison Crowder that UNC turned into a 15-10 lead 90 seconds from half-time. But the rest of the day belonged to Duke, Duke, Duke, which now takes on Atlantic Division champ, undefeated and second-ranked Florida State in the ACC title game Saturday in Charlotte.

It began when Duke’s DeVon Edwards, who has done this before, returned the ensuing kickoff 100 yards through a gaping and unforgivable hole in the Carolina coverage. Edwards, you remember, scored three touchdowns on returns in the second half to torch N.C. State and make ESPN SportsCenter.

Then after capitalizing on one of two Marquise Williams interceptions to begin the second half, the Blue Devils went up by nine points with a second TD pass to Crowder from Anthony Boone who was the best quarterback on the field this day, completing 23 of 34 for 274 yards and no turnovers.

The Tar Heels, still bowl bound after having their five-game winning streak snapped that left them 6-6 on the season, took an early lead set up by a 79-yard pass and run to Eric Ebron, freed by a great block from Sean Tapley. But other than the gift on the Duke muff and a two-point pass from holder and laser punter Tommy Hibbard to kicker Thomas Moore, the Heels played defense for most of the first half.

They had one good stretch in the second half to score 10 straight points and go back ahead 25-24. But it came after the absolute dumbest of their nine penalties on the day — a dead ball personal foul on junior center Russell Bodine in the red zone — had turned a probable touchdown into Moore’s 37 yard field goal (the former East Chapel Hill star earlier missed a 42-yarder).

The penalties, including a fatal illegal block that pinned Carolina at its 8 yard line after Duke had taken its final lead with an answering field goal in the last two minutes, were inexcusable against a smart, disciplined opponent that doesn’t make many mistakes and always seems to have its players in the right position. That’s why Duke is the first Triangle Team to play for the ACC championship in a 14-school football league getting tougher by the minute.

Williams ran the ball gallantly for 104 yards and two touchdowns, hitting Quinshad Davis for UNC’s third, but the sophomore did not deliver enough big plays in the most pressure-packed game of his young career. He completed only 17 of 36 passes, missing nine straight along the way, and one right on the money was dropped by freshman T.J. Logan as he was crossing the goal line.

The turnovers, penalties and other missed opportunities could not compete with a balanced, beautifully prepared Duke team that executed its game plan of ball control to near perfection. The Blue Devils held possession for 35 of the 60 minutes and seemed to convert every big third down by throwing underneath and finding gaps in the Carolina defense. Boone ran the read option expertly, keeping the home team defenders on the field far too long. (Duke converted 8-of-15 third downs compared to 2 of 12 for UNC.)

And when the Tar Heels had chances to turn Duke over, they could not come up with the ball, most notably senior Tre Boston’s dropped interception on the winning field goal drive. Their fate was sealed on Williams’ second pick, a hurried pass from midfield right to that guy Edwards.

The Blue Devils gloated over only their second win in Chapel Hill since the infamous 1989 game. No posing in front of the scoreboard, but a victory lap with the still royal blue Victory Bell that came pretty close to the defeated Carolina team gathered near the tunnel to sing the alma mater, some obviously with tears of disappointment.

“We wanted our seniors to go out the right way on this field, but we just couldn’t get it done,” said Larry Fedora, who watched the frustration of a 1-5 start return when a sixth straight win would have assured another tie for first in the Coastal Division. At least he’ll get to keep his team together for 15 more practices before a bowl trip that will be decided later this week.

Coming into the game, Carolina should have known Duke was no fluke and had to match the Blue Devils with a fast, physical and intelligent effort against a heady opponent that was surely going to contain big playmakers like Ryan Switzer, who was allowed to return one punt and had five receptions for short yardage The Devils did mostly what they wanted to do, the Heels did not.

“I’d love to say that Duke just beat us,” Fedora sighed after going 0-2 against the nearest neighbor. “But we just didn’t make enough plays today to win a football game.”

Well said, Coach.