Senatorial scion and political newcomer Michelle Nunn will be Georgia’s Democratic nominee for the U.S. Senate, as businessman David Perdue and U.S. Rep. Jack Kingston secured spots Tuesday in July’s Republican runoff.

Kingston, of Savannah, narrowly defeated former Georgia Secretary of State Karen Handel for the second runoff slot. U.S. Reps. Phil Gingrey of Marietta and Paul Broun of Athens fell well short in the possible end to their political careers.

“You know one thing we did do tonight: We retired three career politicians,” Perdue told supporters in Buckhead before knowing his runoff foe. “And we’ve got one more to go.”

He added: “We’re going to have a clear choice. We’re going to have a career politician on one side and an outsider with business experience on the other. So our message is going to stay pretty much the same.”

Kingston won big in South Georgia and got enough of the metro Atlanta vote to hold off Handel.

“I think it’s going to be a tough race,” Kingston said of the runoff. “He’s a guy that has very deep pockets and he’s put in $3 million to $4 million already. He’s got his cousin (former Gov. Sonny Perdue) running the campaign, and it’s a well-oiled machine.”

The earliest primary in Georgia’s history also sets up its longest-ever runoff campaign, with the election set for July 22. That’s likely to mean even heavier spending in a GOP Senate race that saw more than $9 million devoted just to television advertising during the primary.

Waiting for the GOP’s winner will be Nunn, the daughter of former U.S. Sen. Sam Nunn and the CEO of Atlanta nonprofit Points of Light, who was quickly declared the winner in the Democratic primary against three little-known foes.

Joined on the stage by volunteers from her campaign and her organization, Nunn offered a victory speech heavy on Washington dysfunction and her ability as an outsider to address it.

“Tonight we send a signal to Washington that we want something different,” she said. “We want civility, we want collaboration, we want problem solving.”

Though her opponent was yet unknown, she said the candidates were embroiled in “acrimony” and inflexibility, which she asserted were not “Georgia values.” She then cited the Georgia state motto of “wisdom, justice, moderation” to raucous cheers.

Nunn and national Democrats, facing what appears to be an uphill fight to retain control of the Senate, watched with glee as the Republican race became increasingly divisive. But Georgia remains a red state, and Nunn will be the underdog in November.

The night was 16 months in the making, after Republican U.S. Sen. Saxby Chambliss announced in January 2013 that he would not seek re-election. Republicans quickly flooded the race to seek the rare opportunity of an open U.S. Senate seat.

Three sitting congressmen gave up re-election to safe seats to leap in. They were joined by Handel, who nearly became governor in 2010, and Perdue, a longtime corporate executive.

Rounding out the field were Atlanta attorney Art Gardner, who took more moderate positions on social issues and immigration and lectured Republicans about needing to expand their base; and Stone Mountain minister and MARTA engineer Derrick Grayson, who brought a fiery presence, celebration of the Constitution and an indictment of the GOP “royals” in charge.

Perdue started as an unknown but poured money — much of it his own — into memorable television advertising depicting his opponents as whining babies and himself as the jean jacket-wearing “outsider” and successful businessman. He rocketed to the front of the polls and then held on as the attacks mounted.

Perdue’s lack of rigidity in tone on issues such as Common Core education standards and tax revenue — even as he agreed with the rest of the field on substance — left him open to attack from the right. In addition, the failure of Pillowtex, a North Carolina textile company he briefly ran, provided fodder for attack ads.

Kingston was the biggest fundraiser and spender, with an additional $1 million boost from favorable ads by the U.S. Chamber of Commerce after the big business lobby endorsed his candidacy.

Perdue struck back only in the final days and somewhat reluctantly. He went after Kingston for approving increases in the federal borrowing limit, the Cash for Clunkers program and generally being in Washington too long.

Handel stayed within striking distance despite trailing big in the money race.

“There’s no shame in doing this well with how little we had to start with,” she said to fewer than 30 supporters in Roswell.

There are now two candidates left, and she called on her supporters to “pick whichever one you feel you can rally around in the runoff.”

Gingrey pledged not to seek re-election after his first term if the Affordable Care Act is not repealed, while Broun relied on a small but highly motivated band of tea party enthusiasts to juice his bid. Neither gained much momentum.

“Well it didn’t work out,” Broun said walking to the stage to thank his supporters in Duluth.

He said: “If God opens a door for a campaign in the future, I’ll be ready.”

Expressing disappointment, Gingrey conceded his loss to backers in Marietta. “I haven’t had to do that in 20 years, but you’re always just one away,” he said. Gingrey said he would support the eventual GOP nominee, but he also said he “probably” would not make an endorsement in the runoff. “It just won’t be me, and I’m disappointed.”

Nunn was anointed by Democrats in Atlanta and Washington as the primary choice and set about raising piles of money across the country.

Her primary opponents — former news anchor and state Sen. Steen Miles of DeKalb County, Atlanta psychiatrist Branko Radulovacki and Columbus firefighter Todd Robinson — struggled to raise money and get attention. Nunn only appeared at one debate, where her three foes hammered her for not going to more and for not embracing the Democratic base.

Outsiders such as Perdue and Nunn would have to overcome quite a bit of history to win — only eight of 100 current U.S. senators have been elected without political experience.