Colorado State extends its school-best record for consecutive home wins to 24.
Greg Smith scored 16 points, and Colton Iverson had seven points and 10 rebounds.
The Rams had a 36-34 rebounding edge and have outrebounded every opponent.
Colorado State (15-3, 2-1 Mountain West) led 31-26 at halftime.
UNLV shot 41 percent from the field for the game, while Colorado State shot 38.9 percent.
Anthony Marshall led UNLV (15-4, 2-2) with 15 of his 21 points in the second half. Katin Reinhardt added 11 points, and Khem Birch had seven rebounds. Prize freshman Anthony Bennett was limited to nine points for the Runnin' Rebels, who had their two-game winning streak snapped.
Colorado State has the nation's fourth-longest home streak and last lost at home on Nov. 19, 2011.