Green Bay (21-5, 11-2 Horizon) jumped out to a 24-5 lead midway through the first half after Brown knocked down a 3-pointer. The Phoenix made just eight more points before the break, but still led 32-19 after shooting 62.5 percent (5 of 8) behind the 3-point arc.
Greg Mays and Jordan Fouse made two baskets apiece in the first 1:20 of the second half to stretch the halftime lead, and the Phoenix were up by as many as 23 in the second half.
Trey Lewis scored 20 points for Cleveland State (18-10, 9-4) and was the only Viking to finish in double digits.
Green Bay was ranked first in the Horizon League entering the game on Saturday.