Jarrett Jack had 15 points for the Yellow Jackets (21-8, 8-7 Atlantic Coast Conference), who had lost 15 straight to Duke, a streak dating to the 1995-96 season.
Georgia Tech gave Duke trouble from the start with its athleticism, pushing the ball up the court and through the Blue Devils' defense. The Yellow Jackets penetrated effectively for good shots, shooting 51 percent and scoring 38 points in the paint.
In addition, Georgia Tech played physical man-to-man defense, blocking 11 shots and holding the Blue Devils to 34 percent shooting. Duke finished with 20 turnovers.
Georgia Tech built a 12-point lead late in the first half and never trailed after that, answering Duke's spurts with runs of their own.
As the final seconds ticked off, Marvin Lewis raised his arms while Jack jumped around as he dribbled the ball. Once the horn sounded, the Yellow Jackets' bench spilled onto the Cameron Indoor Stadium court in celebration.
Redick went 4-for-9 from behind the arc in the second half, and tied the game at 56 with a 3 from the left wing with 7:02 left.
But Schenscher scored six straight points, including a dunk off a feed from Lewis and a layup on a pick-and-roll from Jack.
He also added a stickback, then made two free throws after keeping a possession alive with an offensive rebound for a 67-60 lead with 3:19 left.
Duke got not closer than three points after that, and the Yellow Jackets went 7-for-8 at the free throw line over the last 90 seconds.