Brown netted 23 points and Nash added 20 to lead the Cowboys on offense. On defense, OSU held the Vikings to just 39.6 percent shooting for the game.
Phil Forte connected on 5-of-7 of his shots en route to 15 points for the Cowboys, who are off to their first 5-0 start since the 2009-10 season.
Portland State (1-3) was led by Michael Harthun and Renado Parker with 12 points each.
Swim Week Miami Beach 2014 [PHOTOS]