The Morning After: Thoughts, notes and anything else that didn’t quite make this space after North Carolina’s latest game (in this case, No. 5 UNC's 85-84 loss to No. 9 Duke at the Smith Center on Wednesday).

CHAPEL HILL, N.C. -- Does fifth-ranked North Carolina need to develop more of a killer instinct?

“You can say killer instinct, or you can just say we’ve got to step up under pressure," forward Harrison Barnes said after his team allowed Duke to rally from a 10-point deficit in the final 2 1/2 minutes Wednesday night, and lose on Austin Rivers’ last-second 3-pointer.

“I thought we laid back a little bit, and we made some terrible turnovers down the stretch, and it caught up with us at the end.”

After UNC opened the second half with a 14-4 run to take a 13-point lead, it allowed Duke to stick around instead of increasing that lead to put a comeback out of reach. UNC’s advantage bounced from 10 points to 7 to 12 and back, again, until, in the final 2:38, Duke outscored it 15-4. During that timespan, the Tar Heels committed two turnovers, missed two free throws, allowed three offensive rebounds and saw Tyler Zeller accidentally score for Duke -- when Ryan Kelly’s 3-point attempt bounced off his hand and into the basket.

Point guard Kendall Marshall cautioned that it’s only one loss, and that he thinks, “without a doubt,” the Tar Heels are the best team in the ACC.

“Honestly, I take this game with a grain of salt," the sophomore said. “We played well. If we take away one turnover down the stretch, if we make one more free throw, then obviously, it’s a totally different game. I’m really not frowning against our performance, I feel like we played a good game. But they made winning plays to come out on top.”

And the key, both players said, is to negate those plays (and their own mistakes) in the future.

“We can learn a lot,’’ Barnes said. “That at the end of the day, you just have to man up and get the win. They just wanted it more.”

BARNES’ BIG SECOND HALF: Overshadowed by the loss was Barnes’ big second half.

After missing all four of his shots and scoring six points on free throws in the first half, he added 19 points after halftime, and finished 8-for-16 for the game. He has now topped 1,000 points for his career.

“I was just trying to play harder,’’ Barnes said. “My ankle was obviously bothering me the whole game, but the second half, I just started to get loose, and I thought my teammates did a better job of getting me the ball, and I capitalized."

Some halftime words from coach Roy Williams spurred him, as well.

“Coach just told me that if I didn’t want to play, I could sit on the bench,’’ he said. “He just gave me that ultimatum, and I tried to play harder.”

NO APOLOGIES NEEDED: Williams said Duke coach Mike Krzyzewski and one of the Blue Devils’ assistants apologized for their team’s celebration after Rivers hit the game-winning 3-pointer as time expired. But Williams wasn’t concerned.

“I told them they should be excited about that; that doesn’t bother me at all," Williams said. "When you’re a coach, they coach with a passion, just like we do. They had a passion that they showed when the shot went in ... it’s two great teams fighting as hard as they can fight.”

NO MORE STREAK: The loss halted the longest home winning streak in UNC history at 31. In the Williams era, the Tar Heels are now 4-5 against the Blue Devils at the Smith Center, and 4-4 at Cameron Indoor Stadium.

Follow Robbi Pickeral on Twitter at @bylinerp.