The other top scorers included three players with 13 points -- Marcquise Reed, Gabe DeVoe and Elijah Thomas -- and Shelton Mitchell with 10.
Clemson made 55.9 percent of its field goals and outrebounded North Carolina A&T 45-22.
The Aggies (1-1) were led by Femi Olujobi's 20 points and four rebounds. Devonte Boykins contributed 14 points and three assists.
Clemson (2-0) never trailed and built as much as a 13-point lead in the first half behind the shooting and scoring of DeVoe and rebounding of Grantham.
DeVoe had 11 points on 4-of-5 shooting and Grantham had nine points and seven rebounds by halftime. DeVoe finished with 10 rebounds and Grantham had a game-high 12. Thomas added nine.
Clemson, which led 41-29 at halftime, pulled away at the start of the second half by going on a 12-3 run.
Thomas fueled that run with five points, Grantham added four and North Carolina went 1 of 4 from the field and committed two turnovers in that stretch.
Clemson tallied 21 assists on its 33 field goals made, led by six from Mitchell and five from DeVoe.