Drew Valentine added 17 points, Ryan Bass had 16 and Corey Petros 12 for the Golden Grizzlies (15-13, 10-4 Summit), who hit 10 of 21 3-point attempts and outrebounded the Kangaroos 35-25. Duke Mondy had nine assists for Oakland.
UMKC (7-21, 4-10), which has lost seven of its last eight games, got 18 points from Nelson Kirksey, 17 from Thomas Staton and 11 from Estan Tyler.
The Golden Grizzlies never trailed, leading by as many as 21 when Valentine scored on a tip-in to make it 43-22 with 3:08 left in the first half.
UMKC rallied in the second half, pulling within 76-72 on Staton’s layup with 58 seconds left, but Oakland closed it out with 10 straight free throws in the final minute.
Oakland has beaten the Kangaroos 14 straight times.