Austin Rivers scored 17 points and three-time 56 quarterfinal win over Virginia Tech on Friday.
Tyler Thornton had 13 points and Mason Plumlee added 12 and 11 rebounds for the sixth-ranked Blue Devils (27-5).
Despite the absence of Ryan Kelly for the entire tourney, Duke won its 10th straight ACC Tournament game and advanced to play the winner of Miami- Florida/No. 17 Florida State in Saturday's semifinals.
Erick Green and Robert Brown both scored 16 to pace the Hokies (16-17), who defeated Clemson in Thursday's opening round.