CHICAGO (CBS) — An historic mayoral election has led to an unprecedented runoff contest, with two black women vying to be the next mayor of Chicago.

After a record number of candidates slugged it out for months, the final two left standing are Lori Lightfoot and Toni Preckwinkle.

Both candidates were out greeting voters bright and early Wednesday morning, hours after taking the top two spots in the race. Bill Daley, who was in third place, conceded less than three hours after the polls closed.

Daley and Preckwinkle had been perceived as the two front-runners, but a surprising survey released the day before the election revealed Lightfoot was in a three-way tie with Daley and Preckwinkle.

With approximately 17.5 percent of the vote, according to unofficial totals, Lightfoot held a nearly 7,000-vote lead over Preckwinkle. It was a stunning victory for a candidate who said her win is proof that, with hard work, anything is possible.

Lightfoot, like Preckwinkle, would be the first black woman elected mayor of Chicago; and Lightfoot also would be the city’s first gay mayor.

“It is historic, and I’m incredibly honored and humbled that I was the first LGBTQ+ person ever to be on the ballot for the mayor. I’m humbled that we’ll have only the second female and only the second African-American leader of this great city,” she said.

Preckwinkle also thanked her supporters Wednesday morning, as she visited the 95th/Dan Ryan station on the Red Line.

She acknowledged the historic nature of the runoff election, but quickly pivoted into campaign mode, calling herself the most progressive candidate in the race

Lightfoot said Preckwinkle, the Cook County Board President and chair of the Cook County Democratic Party, is part of the machine. But Preckwinkle said she’s always maintained her independent streak.

“When I was in the City Council, I was the founder of the Progressive Caucus. I supported every single affordable housing and living wage ordinance that came before the body – actually, I was the sponsor – and I was one of five votes against the parking meter deal,” Preckwinkle said.

Because no candidate received a majority of the votes, Lightfoot and Preckwinkle will face off on April 2 in a runoff election.

With Lightfoot and Preckwinkle now facing each other head-on, the candidates will have to scramble to gain support from the other 12 candidates in the field.

CBS 2 Chicago Political Reporter Derrick Blakley said the race matches an insider, Preckwinkle, against an outsider, Lightfoot.

The questions, according to Blakley, are: Which candidate will get the backing of big donors? Who will progressives back? And will the African American community get behind one candidate?

Preckwinkle, the Cook County board president, enjoys strong union support. Lightfoot, a former federal prosecutor who has made a career as a reformer, chaired the task force that proposed reforms at the Chicago Police Department in the wake of a scathing federal report about systemic abuses within CPD.