Trevor Lacey added 21 points for the seventh-seeded Wolfpack (20-12), who reached the 20-win mark for the fourth time in as many seasons under Mark Gottfried.
As it has all season, the playmaking backcourt led N.C. State and caused headaches for the 10th-seeded Panthers, whether it was Barber going wherever he wanted with the ball or Lacey knocking in tough shot after tough shot.
N.C. State shot 53 percent to earn its second double-digit victory this season against Pitt (19-14), a win that will only help an already-solid looking NCAA tournament resume that includes wins against Duke, Louisville and North Carolina.
Now the Wolfpack gets another shot against the No. 2 Blue Devils in the quarterfinals.