CHICAGO — Two African-American women are headed for a runoff in the Chicago mayor’s race, setting up an election that will make history.

Lori Lightfoot, a former federal prosecutor and sharp critic of the status quo at City Hall, won enough votes in Chicago’s election for mayor on Tuesday to advance to a runoff in April, The Associated Press reported.

The closest candidates behind Lightfoot were separated by a small margin, and all the votes had not been counted. But one of them — William M. Daley, a member of Chicago’s political dynasty of Daleys — conceded defeat late Tuesday and said Toni Preckwinkle, the county board president and chairwoman of the county’s Democratic Party, would advance to the runoff.

Either Lightfoot or Preckwinkle would be the first African-American woman to lead the nation’s third largest city, succeeding Mayor Rahm Emanuel as mayor.

Preckwinkle, 71, a long-established politician who has often been urged to run for mayor, had been widely expected to do well Tuesday. The success of Lightfoot, 56, who has never run for elective office before, was far more surprising; she was less well known in Chicago’s political sphere and had far less money.

Her vote total, too, was seen as something of a rebuke to Emanuel’s tenure as mayor and to Chicago’s old political history. Lightfoot had tried to define her campaign as a rejection of machine politics and a refocusing on Chicago’s struggling neighborhoods, not just its gleaming downtown.

“I never thought that this could be an option,” said Liza Booker, 29, a South Side resident who said she voted for Preckwinkle but was excited about the possibility of a runoff between two black women.

With 92 percent of votes counted on Tuesday night, they were sprinkled widely across the massive field of candidates who had hoped to replace Emanuel, who did not run for a third term. Lightfoot had the highest vote tally, with about 17 percent. Preckwinkle had 16 percent, and Daley, who was well funded and many here had expected to easily make the runoff, came in just below 15 percent.

With 14 candidates — more than this city has ever seen before in a mayor’s race — almost no one had expected a new mayor to win outright on Tuesday and avoid a runoff on April 2.

For months, Chicago’s campaign has looked like a reunion of its best-known political figures — a former police superintendent, a former public schools chief, a former city clerk.

Among the names most familiar to voters were Preckwinkle and Daley, a brother of this city’s longest-serving mayor (Richard M.) and a son of the second-longest-serving mayor (Richard J.). Richard M. Daley, who ran Chicago for 22 years before Emanuel arrived in 2011, was sometimes known as “Mayor for Life,” and some Chicagoans thought the Daley name alone would at least advance the latest Daley into a runoff.

But with so many candidates and no clear favorite, the race was seen as up for grabs — a rare circumstance in a city where mayors have more often held office for long stretches and where incumbents are usually on the ballot.

So many choices seemed to have left some Chicagoans flummoxed — unsure, even in the final hours, whom they would vote for. Some political strategists said they wondered if that might discourage some people from voting at all in the election, which is technically nonpartisan, though Democrats reliably win.

On Tuesday, Chicago appeared to be headed for a historically low voter turnout rate. Fewer than 430,000 ballots had been cast by afternoon, including mail-in and early votes, from among the city’s 1.58 million registered voters.

Emanuel upended Chicago’s political landscape when he announced in September that he would not seek a third term. Emanuel — who had been sharply criticized over his handling of school closings, crime and police misconduct and had faced political challengers — said at the time that the mayor’s office “has been the job of a lifetime, but it is not a job for a lifetime.” After that, many more candidates stepped forward.

Whoever becomes the next mayor of this city of 2.7 million people will face an array of complicated, sometimes interconnected, challenges all at once.

The city’s pension system will require an additional $1 billion in revenue by the end of the new mayor’s first term. Yet residents say they are weary from years of increases in their property tax bills and fees. Crime and gang violence remains a deep worry for many, even as the city contends with its long history of troubled relations between the police force and residents, especially in the black community.

And although tourism has boomed downtown, development along the Chicago River has flourished and corporations have flocked to the city in recent years, some neighborhoods on the South and West Sides have struggled with disinvestment, schools closing and people moving away.

On Tuesday, Jackie Ropski, a marketing director for an elementary school, said that she saw this election as more important than some, with so many candidates to choose from and at a pivotal moment in Chicago history.

“I think there is a certain amount of weight on this particular election,” Ropski said, after voting in the Irving Park neighborhood on the Northwest Side. “Personally, I think education takes prominence among all the issues, but whoever is mayor has to take a layered approach. How do you solve poverty, crime, neighborhood tensions, education? That’s complex.”

Alex Ruiz, 33, a student and Uber driver, said that the biggest issue that worried him was Chicago’s financial situation and its looming pension obligations. The next mayor, he said, had to get the city’s finances in order to spread confidence to Chicagoans about the state of the city.

Ruiz grew up only a few miles east of his current neighborhood, Irving Park, but his family had steadily moved west throughout his life as gentrification kept pushing them out.

“Everyone’s trying to stay in this city they were born in,” he said. “If we don’t address the financial issues, we’re going to keep driving the middle class out of the city.”

Jewel Morris, 62, a retired probation officer, said he had voted for Preckwinkle, though he deemed her the “lesser of two evils” compared with William Daley, who is known as Bill.

“No Daleys, no Bushes, no dynasties,” said Morris, who lives on the Near West Side. “We don’t need any of that.”

The Chicago of 2019 is better than when he was a child, he said. The architecture is unparalleled, the restaurants are world-class and tourists are coming to the city in droves. But the inequality feels like the Chicago of his youth.

“You’re looking at a tale of two cities,” he said. “It’s still the city of neighborhoods and still the city of segregation.”

At Manny’s deli, south of downtown, Natalie Wasso said she was leaning toward voting for Daley, if she voted at all.

Wasso, 32, a phlebotomist who lives on the Southwest Side, said she trusted the Daley family, which led the city for most of her childhood. Her grandmother had always voted for Daleys in past elections.

“We never had a problem: That’s the name we know in Chicago,” Wasso said. “He can relate to us regular people.”

This article originally appeared in The New York Times.