ISU (8-17, 3-10) was led by freshman DJ Horne with 16 points while Dedric Boyd came off the bench to score 11 and Keith Fisher III had 10.
The Redbirds made 12 of their first 18 shots in taking a 31-22 lead, but was outscored 18-2 the rest of the half as UNI took a 40-33 halftime lead.
UNI (22-3, 11-2), which lost to the Redbirds, 76-70, on Dec. 31 in Normal, also received 17 points from Trae Berhow and 12 from Austin Phyfe.
ISU entertains Valparaiso at 6 p.m. Saturday at Redbird Arena. Several members of ISU's 1,000th point club, including Doug Collins, will be honored at halftime.