Sampson, who entered the game averaging 6.7 points and seven rebounds, also added 17 points. Kemp, who scored nine of his points from the free-throw line, grabbed 11 rebounds for the Pirates (4-0).
Appalachian State (1-3) scored the game's first four points and led 6-2 after Nathan Healy hit a jumper. But East Carolina used a 14-4 run to go ahead 16-10 with 14:29 left in the first half.
Appalachian State cut the deficit to 23-22 later in the half but would not get any closer as East Carolina took a 38-33 advantage into halftime and never led by less than four in the second half.
Jay Canty had 25 points and Healy added 24 points and 10 rebounds for Appalachian State.
There's nothing to suggest the Jayhawks won't end up atop the Big 12 for a 13th season in a row. But what about a return to the Final Four?
Colorado State graduate transfer John Gillon has chosen Syracuse, giving the Orange a potential starter at point guard entering the 2016-17 season.
DeSean Murray, who averaged 20.2 points as a sophomore at Presbyterian, will transfer to Auburn to play for coach Bruce Pearl.