ATLANTA - Businessman David Perdue has defeated longtime Rep. Jack Kingston in the Republican runoff for Georgia's U.S. Senate nomination, setting up a matchup against Democratic nominee Michelle Nunn that will help determine which party controls the Senate for the final years of the Obama administration.

Tuesday night's primary runoff win validates Perdue's campaign as an outsider. The former CEO of Reebok, Dollar General and the failed textile firm Pillowtex, Perdue offered his private sector record and tremendous wealth as proof that he can help solve the nation's ills in a Congress largely devoid of experience business titans.

He spent more than $3 million of his own money blasting Kingston and other primary rivals as career politicians, including one ad depicting his rivals as crying babies.

"I've never run for anything in my life. I'm humbled," Perdue told supporters gathered at a hotel in the Buckhead neighborhood of Atlanta.

Perdue won handily in Dawson County, earning 62.24 percent of the vote.

Perdue immediately shifted to general election mode, praising Kingston and calling for party unity in the race against Nunn and Libertarian Amanda Swafford of Flowery Branch.

Across town on the Georgia Tech campus, Kingston thanked his supporters and let them know he'll be working for a Perdue win in November. "We will keep Georgia in the Republican column," he said.