Colorado State had its chances. But poor execution down the stretch and a few bad breaks continued the Rams' dismal history at Viejas Arena.
John Gillon missed a potential game-tying layup just before the final buzzer, and San Diego State survived to hand CSU its 13th straight loss at SDSU, 69-67, late Tuesday night.
The Aztecs (17-6, 10-0 Mountain West) remained unbeaten in conference play to retain a 2 1/2 game lead on New Mexico (14-8, 7-2).
The Rams (12-10, 4-5 MW) lost their second straight and fell a game behind fifth-place Nevada, which visits CSU on Saturday.