The Democrat faced Unity candidate Lance Tyson and write-in Democrat Eddie Winters.
Smith refused to take his name off the ballot after federal prosecutors claimed he accepted a $7,000 cash bribe in an FBI sting in exchange for what he thought was a letter of support for a daycare center's state grant application. He has pleaded not guilty.
Tyson had the support of regular Democrats - including an endorsement from Gov. Pat Quinn - who had abandoned Smith after his March arrest.
The Democratic-controlled House ejected Smith in August, but the Illinois Constitution prohibits expelling a lawmaker more than once for the same offense.
The Associated Press contributed to this report.