ATLANTA — For the second time in eight years, the leadership of the South’s most influential city is likely to be settled after a recount.

Fewer than 800 votes separated Atlanta’s two candidates for mayor, Keisha Lance Bottoms and Mary Norwood, after officials tallied more than 92,000 ballots that were cast in a runoff election on Tuesday, according to preliminary returns. The margin was narrow enough that Ms. Norwood, seeking to become Atlanta’s first white mayor in more than 40 years, said she would ask for a recount once provisional and absentee ballots were counted this week.

But Ms. Bottoms and her allies declared victory on Wednesday.

“This has been a very, very, very long campaign, but as we look ahead toward the future, I look forward to engaging with each of you, making sure that our city continues to move forward,” said Ms. Bottoms, who is a member of the City Council from Southwest Atlanta. “And for those who did not support me, I look forward to working with you as well because this is still a city for all of us.”

After a fractious campaign in which race was a persistent undercurrent, it was perhaps unsurprising that the contest would endure a last dash of turmoil. But the call for a recount gave Wednesday’s aftermath a surreal edge: In 2009, Ms. Norwood sought a recount when she trailed in the mayoral election.