Neither team led by more than six points in the second half going down the stretch and the game was tied at 65 with 2:58 to play.
Justin Schwartz then hit a bucket at he 2:43 mark to give SU a 67-65 lead. Dathan Jones split a pair of free throws to make it 67-66. Schwartz and Jarrell Williams hit back-to-back 3-pointers, making it 73-66 with 1:40 to play.
The two teams were tied 33 at halftime. HSU jumped out to a 7-0 lead to start the game. Schreiner lead by as many as eight in the first stanza.
The Cowboys fall to 5-12 on the season and to 3-3 in league play. Schreiner improved to 8-9 and 1-7 in ASC West play. Adam Shoupe led the Cowboy effort with 15. Justin Schwartz led SU with 16.
HSU will return to action Saturday at Texas Lutheran at 3 p.m.