Paul Egwuonwu added 14 points and seven rebounds for the Bobcats (4-7, 1-2 Big Sky).
Montana State led 52-38 with 7:35 remaining when Portland State went on a 15-1 run to tie the game at 53-53 with 3:05 to go.
Two jumpers by Egwuonwu and four free throws from Moon put the Bobcats ahead 61-53 with 12 seconds left. But McMullen hit a 3-pointer with 5 seconds remaining, then made a steal and another 3-pointer with 3 seconds left to make it 61-59.
Michael Dison hit 1 of 2 free throws for Montana State before a desperation 3-pointer by Dre Winston at the buzzer came up short.
In a decade at Ole Miss, Andy Kennedy has seemingly worked wonders with limited talent at a program that has rarely had success historically.
Hal "King" Lear, a Temple basketball star during the 1950s, died Saturday at his White Plains, New York home.
Sebastien Bellin's friend Chris Young joins Ryan Smith on Outside the Lines to discuss his friend's bravery, courage and strength after surviving the Brussels bombings in March.