ISU, which improved to 10-20 overall and 5-13 in the Valley, played without Keith Fisher III because of an illness. Jaycee Hillsman added 13 points.
Matt Chastain, who played for the first time since Jan. 22 because of arthroscopic knee surgery, chipped in five points and six rebounds for the Redbirds. That included a 3-pointer with ISU leading 54-53 that started a 12-4 run which put the game away.
Evansville (9-22, 0-18) became the first Valley team in 21 years to go winless in the league. The Purple Aces were led by senior K.J. Riley with 18 points.