Cooper Flagg scored 14 of his 24 points in the first half as No. 4 Duke took care of business in an 88-65 victory against visiting Virginia Tech on Tuesday at Durham, N.C.Tyrese Proctor and Kon Knueppel both had 13 points, Isaiah Evans notched 12 points and Sion James and Mason Gillis each finished with 10 points as the Blue Devils (11-2, 3-0 Atlantic Coast Conference) won their seventh game in a row. James also collected 11 rebounds.Duke had flashes of dominance during its ACC home opener, particularly with a big second half.Tobi Lawal had 19 points, with 15 in the second half, for Virginia Tech (5-8, 0-2), which has lost two in a row. Patrick Wessler had 10 points off the bench.Flagg had two 3-point baskets among his 9-for-14 shooting from the field. He also finished with a game-high six assists.The Hokies hung around, pulling within 49-40 with less than 13 minutes left. Proctor and Evans drained 3-pointers on Duke’s next two possessions.Lawal had 11 of Virginia Tech’s first 15 second-half points.But the Hokies had trouble converting in the lane and were held to four points across a stretch of more than four minutes as Duke stretched the margin to 61-44.