In his first bid for public office, Rauner on Tuesday topped state Sens. Bill Brady and Kirk Dillard and Treasurer Dan Rutherford.
The wealthy venture capitalist from Winnetka in November will face Democratic governor Pat Quinn, who had a lesser-known primary challenger.
Rauner ran on a promise to “shake up” Springfield and the “career politicians” and special interests he says helped create Illinois’ financial problems.
A virtual unknown when he got in the race, Rauner spent more than $14 million, including about $6 million of his own money.
Much of the money went toward TV ads that helped him increase his name recognition and fight back against attacks from organized labor.