Terrence Shannon Jr. scored 30 points, Marcus Domask added 22 and Illinois made fast work of its 11th-seeded opponent from the Atlantic 10 in the third-seeded Illini's 89-63 victory over Duquesne on Saturday night.
Illinois (28-8) hadn't made it through the first weekend of the tournament in eight previous appearances.
Illinois and Iowa State will play in the NCAA Tournament for the first time. Illinois has won nine of the last 12 meetings but lost the last two, in 2018 and 2015.