Cooper Flagg didn't just introduce himself to the Duke-North Carolina rivalry on Saturday. He marked Tobacco Road as his territory in a lopsided Blue Devils win.

The freshman sensation finished with 21 points, eight rebounds, seven assists, three steals and two blocks in No. 2 Duke's 87-70 win over the Tar Heels at Cameron Indoor Stadium. Head coach Jon Scheyer took Flagg out of the game with 48 seconds remaining and the Blue Devils holding a 20-point lead.

With the victory, Duke stayed undefeated in the ACC at 11-0 and improved its overall record to 19-2. Since losing to then-No. 1 Kansas in late November, the Blue Devils have won 15 consecutive games.

Flagg made an immediate contribution, assisting on Duke's first basket of the game with a pass to Sion James for a dunk. The freshman then broke a 2-2 tie with his first 3-pointer and ignited a torrid start for the Blue Devils.

Duke quickly built a 23-6 lead with Flagg contributing six points during the run. But he made an impact on both sides of the floor, getting steals and protecting the rim on defense as well.

The Blue Devils took a 47-25 lead into halftime (with Flagg hitting a fadeaway jumper before the buzzer). It was a nightmarish first half for the Tar Heels, who shot 29.6% (and 27% on 3s) — their worst-shooting half and fewest points scored in a half this season. UNC also committed 10 turnovers. The 22-point halftime deficit was the largest in the rivalry during the past 30 years.

Flagg had 13 points in the opening 20 minutes with four rebounds, five assists, two steals and two blocks, shooting 4-of-7 from the floor.

Duke continued the barrage to begin the second half with Kon Knueppel scoring the first five points on a dunk (with an assist from Flagg) and 3-pointer. The fellow freshman led the Blue Devils with 22 points, and added five assists and two steals. Tyrese Proctor tallied 17 points.

At one point, the Blue Devils led by 32 points, 77-45, and looked like they could surpass the 35-point margin in their biggest win over North Carolina. Duke defeated the Tar Heels, 104-69, at Chapel Hill in 1964. (UNC's largest margin of victory over Duke is 37 points, winning 55-18 in 1921 at Raleigh.)

RJ Davis and Drake Powell each scored 12 points for UNC, followed by Seth Trimble's 10. UNC dropped to 14-9 and 6-5 in conference play. Hopefully, the free pizza that Carolina fraternity houses received from football coach Bill Belichick before the game was tasty.

Duke will attempt to stay undefeated in ACC play with a visit to Syracuse (9-12, 3-7) on Wednesday. North Carolina has a week before trying to bounce back by hosting Pittsburgh (14-7, 5-5).