Kon Knueppel scored 17 points and Tyrese Proctor and Sion James both notched 16, and No. 2 Duke responded from a seven-point deficit in the second half to beat rival North Carolina 82-69 on Saturday night at Chapel Hill, N.C.Duke clinched the outright regular-season championship in the Atlantic Coast Conference.Foul-plagued Cooper Flagg added 15 points for the Blue Devils (28-3, 19-1 ACC) to aid in the road victory and a two-game sweep of the regular-season series.A loss would have sent Duke into a three-way tie for first place and resulted in the third seed for next week’s ACC tournament in Charlotte.RJ Davis scored 20 points and reserve Ven-Allen Lubin added 11 points for the Tar Heels. North Carolina (20-12, 13-7) was in desperate need of a quality victory to boost its NCAA Tournament hopes, but had its six-game winning streak snapped instead.Duke’s 22-5 run turned a 59-53 deficit into a 75-64 lead with 4:58 remaining.