With 96 percent of the precincts counted, the Secretary of State's office said Wednesday Chambliss had 49.9 percent of the vote, the Atlanta Journal-Constitution reported. Georgia law requires a runoff if no one reaches 50 percent plus 1.
Martin had 46.7 percent while Libertarian candidate Allen Buckley took a critical 3.4 percent of Tuesday's vote.
"We're in a runoff," Martin said. "The runoff race begins right now."