Grant, the son of former Oklahoma standout Harvey Grant and nephew of Clemson great Horace, jammed home the game's first basket and never let up for the Tigers (10-2). He finished with 12 points.
The win spoiled the return of former Georgia Tech coach -- and current Cougars leader -- Bobby Cremins to Littlejohn Coliseum.
Cremins hadn't coached at Clemson since Feb. 2, 2000, in his final season with the Yellow Jackets.
Andrew Goudelock scored 17 points to lead the Cougars (4-4).
Clemson has won its past four since blowing a 23-point second-half lead at home to lose to Illinois 76-74 on Dec. 2. The Tigers also reached double digit victories before the New Year's Day for the fifth consecutive season.