With the loss, SIU can no longer finish better than fourth in the Missouri Valley Conference.
SIU (21-9, 10-7 MVC) scored 15 points in the first period, shooting 20 percent from the field (5-25). Illinois State (18-12, 12-5 MVC) took advantage of the Salukis' woes, taking a 21-point halftime lead.
Redbird sophomore guard Paris Lee tied the entire Saluki team by himself in the first half. He finished with a game-high 21 points.
The Dawgs turned around their shooting in the second half, shooting 41.4 percent but still allowed Illinois State to shoot 48 percent.
Senior guard Anthony Beane struggled from the field, with just two points.