Senior Matt Gatens hit clutch free throws down the stretch and scored 20 points on 7-12 shooting from the floor.
Iowa trailed by 7 points in the second half before solid play pulled them even. Iowa was ahead by as much as 7 before Illinois closed to within 1 point.
The win was Iowa’s first since 2006 in the tournament. Iowa will play #1 seed Michigan State in the second round.