Stacey Abrams, the Democratic candidate for Georgia governor, addressed supporters early Wednesday morning and told them to expect a runoff against Republican Brian Kemp.
"Georgia still has a decision to make," Abrams said. "If I wasn't your first choice, or if you didn't vote, you're going to have a chance to do a do-over."
NBC News says the race is too close to call.
Under Georgia law, if no candidate wins more than 50 percent of the vote, then the top two vote getters advance to a runoff election.
With 99 percent of precincts reporting at 11:00 a.m. ET, Kemp had 50.4 percent, or 1,969,355 votes, Abrams has 48.7 percent, or 1,902,526 votes, and Libertarian Party candidate Ted Metz had 0.9 percent, or 36,958 votes.
However, there are reports of thousands of uncounted absentee ballots, in addition to an unknown number of provisional ballots.
Any runoff would be held on Dec. 4 and would be the first general election runoff for governor in Georgia.
Abrams, who is seeking to become the first African-American woman elected governor in U.S. history, alluded to allegations of voter suppression.
"This election has tested our faith," she said Wednesday. "I'm not going to name names, but some have worked hard to take our voices away."
On a call with reporters later Wednesday morning, the Abrams campaign said they believed thousands of absentee and mail-in ballots are still trickling in, which could help push them into a runoff. The Abrams campaign also reiterated their commitment to making sure every vote is counted and said they will pursue "all options" moving forward.
Kemp, who oversees elections as secretary of state, has until Nov. 20 to officially certify the election. A candidate cannot officially request a recount until the certification.
Kemp came under fire early on from Democrats and civil rights organizations who accused him of slow-walking voter registration and purging voter rolls — actions which tend to disproportionately affect African American and minority voters — in order to suppress the black vote and tilt the election in his favor.
Democrats, including former President Jimmy Carter, have charged Kemp with abusing his office and called for him to step down from his position while running for governor.
Instead, just two days before the election, Kemp fired back, announcing his office was investigating the state Democratic Party for allegedly attempting to hack voter registration files. Kemp provided no evidence for the allegations and Abrams branded it a "witch hunt."
As polls closed on Tuesday, Georgia voters filed a lawsuit against Kemp claiming he is unable to impartially administer a vote recount or oversee the remainder of the election.