McMullan was 7 of 9 from the field and had four assists and four steals.
Michael Harthun scored 13 points, and Renado Parker had 10 points and six rebounds. Aaron Moore led with seven rebounds.
The score was tied at 28 at halftime. Idaho State pulled within one, 47-46, at 8:12 in the second half, but Portland State went on a run, increasing its lead to 12, 58-46. The Bengals would not get close again.
Portland State (3-5) shot 53 percent from the field for the game, while Idaho State shot 46.8 percent. Idaho State’s largest lead was by four points at 15:08 in the second half.
Melvin Morgan led the Bengals (1-8) with 17 points. Neveij Walters had eight points and seven rebounds.