Brockeith Pane added 11 points for the Aggies (2-1). The Thunderbirds were led by Jackson Stevenett with 19 points, Matt Massey 16 and Wade Collie with 10.
Southern Utah led for much of the second half, leading 37-30 with 15:10 to play. Five consecutive points by reserve center Jordan Stone helped Utah State stay close, though, with the Aggies taking the lead 42-41 on a Pane jumper with 11:40 left.
Reed scored all of his points in the second half.
Southern Utah pulled to within to 59-57, thanks to timely shooting from the free-throw line, before Reed threw down a dunk to give Utah State a 61-57 lead with less than a minute to play.