Kasim Reed led with 99 percent of precincts reporting, but city councilwoman Mary Norwood told supporters that she was not conceding and was open to a recount. Under Georgia law, the runner-up can petition for one when the margin of victory is less than 1 percent of the total vote. Voters cast 84,076 ballots, so the margin would be within the percentage.
The results left campaign-weary voters still waiting for the final chapter in the race that came down to a runoff after the Nov. 3 general election left no candidate in a crowded field gaining 50 percent of the vote plus one to win. Norwood came the closest with 46 percent, compared with Reed's 36 percent.
Reed, 40, and Norwood, 57, have waged a hard-fought battle across the city and over the airwaves in the month leading up to the runoff. Both tried to gain a critical mass of racial crossover votes in the city that has a black majority. Norwood was trying to become the first white mayor in more than three decades.
Turnout was expected to be low, but surpassed the Nov. 3 total of 78,324 by more than 5,700 ballots.
Reed claimed victory at his downtown campaign headquarters.
"Guess who's going to be the 59th mayor of Atlanta?" he said to supporters early Wednesday.
Norwood wanted to wait and see.
"Tomorrow we will see where it all ends up," she said. "It is closer than any of us thought and it has been a harder campaign than any of us thought. We have not gotten enough good information from the county to know that all the votes have been counted."
Fulton County Board of Elections Director Barry Gardner said provisional ballots would be counted on Thursday, and that the election would be certified at noon on Saturday. Norwood would have until Tuesday at 5 p.m. to request a recount if she has not already done so.
The city's changing racial demographics could have played a role in the outcome. In 2000, Atlanta was 33 percent white and 61 percent black. In 2007, the numbers were 38 percent white and 57 percent black, according to the U.S. Census. Experts said victory could have hinged on black-vs.-white turnout.
Odie Donald considered both candidates, but ultimately went with Reed. The 31-year-old said he admired Norwood's commitment to the city, but chose Reed because he felt he would get things done. Donald, who is black, said race was not a deciding factor.
"I can't necessarily say that weighed heavily into my decision," Donald said. "It's like an added bonus."
The winner will inherit a list of challenges after taking office on Jan. 4, including the city's sagging finances, easing citizens' fears about crime, fostering a working relationship with state lawmakers and returning the city to its reputation as the jewel and economic engine of the South and The City Too Busy to Hate.
Reed, who resigned from the Senate to run, steadily gained momentum in the runoff, with a blitz of endorsements that have kept his name in the local media. He raised more money during the runoff, but Norwood had more cash on hand entering the final stretch of the campaign. The latest finance reports showed Norwood spent about $566,000 in the runoff compared to Reed's $790,000.