The Hoosiers (10-4) lost their Big Ten Conference opener to the Illini, 83-80.
Rayvonte Rice led Illinois with 29 points and Tracy Abrams added 17.
Yogi Ferrell led Indiana with a game-high 30 points, and played 43 minutes, staying on the court through the overtime. Hoosiers freshman Noah Vonleh finished with 16 points and nine rebounds.