Estan Tyler and Michael Gholston had 10 points each for the Kangaroos (4-4, 1-0 Summit League).
Frank Gaines scored 23 points for the Mastodons (2-3, 0-1), but shot just 8 for 23 from the floor. Trey McCorkle added 18 points.
UMKC took control for good with an 11-2 run during a 2:40 stretch of the second half. Chamberlain started it with a three-point play, and Gholston had two 3-pointers during the surge, the second giving the Kangaroos a 59-46 edge with 11:26 remaining.