Turnout topped out at 10 percent between advance and Election Day voting, with 11,745 ballots cast from a voter pool of 117,327.
In the 11 U.S. District 10 precincts, 3,661 Republicans cast 1,965 votes, or 54 percent, for trucking company owner Mike Collins and 1,696 votes, or 46 percent, for radio talk show host Jody Hice.
Turnout was 14 percent for that race, out of 26,581 registered voters.
The winner will be the Republican nominee for the seat vacated by Congressman Paul C. Broun, who resigned his post to run for the U.S. Senate and garnered 9 percent of the vote in the May 20 primary.
In the 25-county District 10, statewide results from 17 counties as of 9:30 p.m. place Hice at the forefront, with 26,000, or 54 percent, to Collins' 22,130, or 46 percent.
Tonight's winner will face Democrat Kenneth Dious in the Nov. 4 election.
Provisional ballots are not included in tonight's results. Results are unofficial until certified.
In other races, Henry County voters supported David Perdue over Jack Kingston as the Republican nominee for U.S. Senator.
Republicans also chose Michael Buck over Richard Woods for state school superintendent.
Democrats favored Valarie Wilson over Alisha Morgan for superintendent by a nearly two-to-one margin.
As of 10 p.m., the U.S. Senate and Republican state school superintendent races were neck-and-neck statewide, with Wilson pulling slightly ahead of Morgan.