N.C. State took down second-ranked Duke for the second year in a row Saturday night at PNC Arena. Last year’s game at Cameron Indoor Stadium came down to the final possession, but this game was rarely in doubt.

N.C. State led for the entire second half and went on to beat Duke 96-85. Duke falls to 13-2 on the season and 1-2 in the ACC. It is also Duke’s second loss in four games.

Duke has trailed at halftime six times this season. In those games, the Blue Devils are now 4-2.

Here are five observation Saturday’s game:

1. Grayson Allen did not play well. And as a result, Duke struggled offensively. The 6-5, 205-pound senior guard had one of his worst performances of the season. He scored only eight points. He also took only nine shots. Allen was 3-for-9 from the floor and 1-for-4 from behind the 3-point line. Usually when Allen isn’t shooting much, it’s because he’s trying to be a facilitator.

In this game, he was neither. He didn’t appear aggressive. When asked about his lack of shooting, Allen said it felt like N.C. State was denying him the ball, so he just wasn’t shooting the ball as much.

Duke coach Mike Krzyzewski said the Blue Devils need Allen to either “play well all the time,” or “be strong all the time.”

“Again I’m not blaming it on him, but when it’s not there, you know it’s not there and it just hurts you in every way,” Krzyzewski said. “This group only has one veteran like that. The youth can show more if that one veteran is having a human night where it’s not good.”

2. Duke’s defense continues to struggle. Defense is one of the few reasons Duke has struggled this year. N.C. State scored 96 points against Duke, its fourth highest point total in 16 games this season. The Wolfpack had struggled in recent games. It scored 58 against Notre Dame on Jan. 3, and 62 against Clemson on Dec. 30.

But it found a spark against Duke. N.C. State shot 51 percent from floor overall.

“It’s not like some altruistic thing here, or the world is going to change or whatever,” Krzyzewski said after the game. “We played crappy defense. We were a little frantic, they played their butts off, we’ve got to get better. To me it’s that simple. Now the process of getting there, that’s what we’ve got to figure out.”

He said so far Duke has been able to do that and he hopes they’ll be able to figure it out again.

“If we don’t, then you’re going to see us lose again, and then you’ll ask, are we working on our defense, and I’ll tell you ‘we are working on our defense but it’s not working.’”

3. N.C. State beat Duke on the offensive boards. Duke started the game in its usual form, rebounding its own misses. Through the first four minutes, Duke had four offensive rebounds, while N.C. State had only one defensive rebound. That meant Duke was rebounding 80 percent of its misses, while N.C. State was rebounding only 20 percent of Duke’s misses.

Duke is the best offensive rebounding team in the country. Prior to the game, it cleaned up 41.7 percent of its misses. Freshman forwards Marvin Bagley III and Wendell Carter Jr. have both been dominant on the offensive glass.

But N.C. State buckled down, and seemed to just play a little harder. N.C. State actually finished with more offensive rebounds than Duke did, 14-12. N.C. State’s 14 offensive rebounds led to 20 second-chance points.

“We’ve got to do something because this is not cool at all, just going through and going through the motions,” Bagley said.

4. Duke’s bench scored four points the entire game. Bench production has been an issue for the entire season. Krzyzewski said Duke just doesn’t have a deep bench this year.

He said Duke freshman guard Alex O’Connell appeared nervous on Saturday.

Duke was also without sophomore center Marques Bolden (3.7 ppg, 3.4 rpg), a 6-11, 246-pound sophomore center for Saturday’s game. He suffered a MCL sprain in practice. Krzyzewski said they thought he might be good enough to play until the day of the game.

5. N.C. State’s Omer Yurtseven was a problem for Duke’s big men. Yurtseven, a 7-foot, 245-pound center, made life difficult for Duke’s big men. He altered shots at the rim and took Duke’s Carter off his game.

On one possession early in the second half, Carter grabbed a rebound under N.C. State’s basket. Yurtseven snatched the ball from Carter’s hands and dunked the basketball with 17:22 left in the game. That bucket put N.C. State up 51-45. Krzyzewski immediately called a timeout and replaced Carter with 7-foot sophomore center Antonio Vrankovic.

Yurtseven finished with 16 points (8-for-14), 9 rebounds and 3 blocks.