ATLANTA (AP) — Businessman David Perdue has defeated longtime Rep. Jack Kingston in a Republican runoff for Georgia’s U.S. Senate nomination, setting up a general election matchup against Democrat Michelle Nunn.

On Tuesday night, unofficial returns showed Perdue with a lead of more than 6,000 votes, with about 93 percent of precincts reporting.

Perdue is a former corporate CEO making his first bid for public office. He campaigned as an outsider and called Kingston a career politician who has done little to solve the nation’s problems.

Kingston is an 11-term congressman from Savannah.

The Perdue-Nunn race will be one of the most critical matchups of the November midterm elections.

Republicans need six more seats to win Senate control for the final two years of President Barack Obama’s administration. The GOP cannot afford to lose retiring Sen. Saxby Chambliss’ seat.

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