Krishnamoorthi and DiCianni were both trying to win the seat vacated by Tammy Duckworth, who won Illinois' U.S. Senate seat Tuesday night.
Krishnamoorthi thanked supporters in a victory speech Tuesday, calling it a "difficult" and "disheartening" campaign season. He says what unites people far outweighs what divides them and that everyone should work together.
He also touched on issues including security and paid parental leave.
"We are going to work tirelessly to grow and strengthen the middle class, to make sure that the working core have ladders of opportunities in the middle class, that those who are there can remain there and that those who want to jump and create wealth and prosperity for their community and country can do that too," he said.
Krishnamoorthi made an unsuccessful congressional bid in 2012 and narrowly lost the 2010 Democratic primary for Illinois comptroller.
The two candidates faced off in a debate last month and moderated by ABC7's Alan Krashesky and Univision Chicago's Enrique Rodriguez.
The Associated Press contributed to this report.