Longtime Democratic incumbent Congressman Mike McIntyre and Republican challenger state Sen. David Rouzer are headed to a recount.
Merely 507 votes separated the candidates, according to unofficial results.
The 7th Congressional District was redrawn by the Republican-controlled state legislature to McIntyre's disadvantage, adding in traditionally Republican strongholds along with new territory for him stretching from the coast to Johnston County.
Millions of dollars of outside money have gone into the race, making it one of the most expensive House campaigns in the country.
More than $6million was spent, most of it favoring Rouzer. Seventy-five percent of the money raised on Rouzer's behalf has come from outside interests: the national organizations Young Guns Network, Young Guns Action Fund, Congressional Leadership Fund and the National Republican Congressional Committee.
Half of the money on McIntyre's side is from outside sources: the House Majority PAC and the Democratic Congressional Campaign Committee.
Counting just the candidates' campaign committees alone, nearly three-fourths of Rouzer's contributors have been individuals.