The Rams made seven of their last 10 shots while the Golden Grizzlies were just three of their last 15 until hitting two late 3-pointers.
Joe De Ciman added 18 points, John Gillon 17 and Antwan Scott 15 for Colorado State (3-0), which made all 11 of its free throws in the second half to finish 23 of 28.
Kahlil Felder had 23 points and 10 assists and Percy Gibson added 18 points with nine rebounds for Oakland (1-1), which started a six-game road trip.
Scott broke a tie with a 3-pointer with 2:44 left and after two Oakland misses, De Ciman hit a 3. Oakland missed two more before Gillon made the first two of his six-straight free throws for a 91-83 lead with 1:15 left.