No. 4 Duke 69, North Carolina 53: Seth Curry scored 18 of his 20 points before the break as the visiting Blue Devils shot a blistering 69.2 percent in the first half to complete a regular-season sweep of the Tar Heels.Mason Plumlee posted his 17th double-double of the season with 23 points and 13 rebounds for Duke (27-4, 14-4 ACC), which defeated North Carolina for the seventh time in the last nine meetings and will enter next week's ACC tournament as the No. 2 seed. James Michael McAdoo had 15 points and P.J. Hairston added 14 to pace North Carolina (22-9, 12-6). The Tar Heels suffered only their second loss over the last eight games - both to Duke - and secured the No. 3 seed in the ACC tournament.Curry sparked the Blue Devils' offense early, scoring seven points as Duke hit its first six shots and forced the Tar Heels into three turnovers during a 14-0 run over the first 3:26. McAdoo answered with North Carolina's first seven points to briefly stem the tide, but three straight jumpers from Curry later in the first half stretched the lead to 28-11 with 10:33 left before intermission.North Carolina, which shot 27.3 percent in the opening 20 minutes and 33.9 percent for the game, could get no closer than 14 points the rest of the way. Plumlee took advantage of an undersized Tar Heels' frontcourt with 10 consecutive points to open the second half as Duke's cushion grew to 61-36 with 9:47 remaining.GAME NOTEBOOK: Plumlee and Curry combined to shoot 18-of-28 from the field. …North Carolina missed its first 11 3-pointers and did not make one until Hairston delivered with five minutes remaining. The Tar Heels finished 1-of-14 beyond the arc. …Duke F Ryan Kelly, who was averaging 27 points since his return from a foot injury last Saturday, scored only eight points.