Perdue pulled off his narrow win by running hard as the outsider, positioning himself from the beginning of the primary as the only non-politician in the race.
He stuck with that message throughout the primary runoff, hammering Kingston as a career politician and criticizing him for his more than two decades in Congress.
Kingston responded by painting Perdue as wealthy and out of touch, ripping into his business record. Those attacks will likely be reprised by Democrats this fall.
Perdue, a self-funding candidate, the former CEO of Dollar General and Reebok, and the cousin of former Georgia Gov. Sonny Perdue (R), took first place in the crowded multi-candidate May primary, leading Kingston by double digits. But Kingston came out fighting, winning the endorsements of many of his congressional colleagues as well as some Tea Party activists.
"Congratulations to David Perdue on his victory tonight in Georgia," National Republican Senatorial Committee Chairman Jerry Moran (R-Kan.) said in a statement. "David's experience in the private sector will be put to good use in Washington, and his firsthand experience in creating thousands of good paying jobs will help Georgians."
Perdue likely starts off with the edge against Nunn in the Republican-leaning state. But Democrats are bullish about Nunn's profile as a centrist former charity executive and daughter of popular former Sen. Sam Nunn (D-Ga.).
Republican strategists were happy to see Perdue and Kingston make the runoff over more flawed candidates like Reps. Paul Broun (R-Ga.) and Phil Gingrey (R-Ga.). But they admit the drawn out and expensive runoff has taken a toll, both financially and on Perdue's image. Nunn has led Perdue in a few recent public polls.
It remains to be seen how much more Perdue is willing to self-fund. He's already given his campaign $1.9 million, but had less than $800,000 in the bank as of the end of June, while Nunn is sitting on a $2.3 million war chest.
Democrats plan to pound Perdue as a heartless corporate raider, picking apart his business record for examples of outsourcing and layoffs, and accusing him of conflicts of interest.
"David Perdue has spent his career tearing apart companies and communities by slashing thousands of jobs in Georgia and across the country and outsourcing jobs to Asia, while walking away with millions for himself," Democratic Senatorial Campaign Committee Executive Director Guy Cecil said in a statement. "It's clear multi-millionaire David Perdue is only looking out for himself — his shady business dealings have left companies billions in debt and bankrupt while leaving thousands jobless."
Republicans, meanwhile, have sought to tie Nunn to President Obama, who is deeply unpopular with Georgia voters.
"David Perdue is a stark contrast to President Obama and Harry Reid's 'top recruit' Michelle Nunn who repeatedly refuses to take a stand on the issues including ObamaCare," Moran said. "David's momentum will force Nunn to stop hiding and start answering the tough questions that she's ducked up until now."
— This post was updated at 11:10 p.m.