(Bloomberg) -- Former New York Governor Andrew Cuomo conceded to his upstart rival Zohran Mamdani in the Democratic primary in the race to become mayor of New York City after the 33-year-old Queens lawmaker racked up commanding leads across Brooklyn, Queens and Manhattan.

“Tonight was not our night,” Cuomo said Tuesday evening addressing supporters. “I want to applaud the assemblyman for a really smart and good and impactful campaign. Tonight is his night. He deserved it. He won.”

In the first round of ranked-choice voting, Mamdani garnered 43.5% of the vote and Cuomo 36.4%, according to preliminary results from the city Board of Elections with more than 95% of the ballots counted. Coming in third place on the first round was city Comptroller Brad Lander, at 11.4%. Lander and Mamdani had cross-endorsed each other.

“The surge by Mamdani is something I’ve never seen before in New York City politics,” J.C. Polanco, a political analyst at the University of Mount Saint Vincent, said before the results were known. “It’s been an incredible campaign that understood social media and marketing like no other.”

Mamdani Leads Cuomo After First Round in Bid for Mayor | NYC mayoral primary results, by vote share

The result isn’t yet official. Under the city’s ranked-choice system, a candidate is declared the winner after receiving more than 50% of the votes. In each round, a candidate will be eliminated and their voters’ No. 2 choice will be distributed to the remaining candidates. The process is repeated until a candidate receives a majority. The next rounds of tallying votes are scheduled for July 1.

Cuomo said he plans to “look at all the numbers as they come in and analyze the rank choice voting,” according to a statement, which suggested he may run for Mayor as an independent in the November election.

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In recent years, the Democratic nominee for mayor of deep-blue New York has been a shoo-in in the general election. But this year Mamdani still needs to face Mayor Eric Adams, who won the 2021 election as a Democrat but is running this time as an independent, as well as Republican Curtis Sliwa and independent Jim Walden, and potentially Cuomo.

Mamdani and Cuomo, 67, offered starkly different visions on taxes and policing in a race that at times mirrored the divisions roiling the Democratic Party nationally. The election also became a microcosm of New Yorkers’ views on ongoing conflicts in the Middle East, with Cuomo pledging support for Israel as Mamdani criticized the country’s wars in Gaza and Iran.

The former governor, the oldest candidate and the person with the most experience working in government, pitched himself as a seasoned moderate who can manage New York’s problems — from crime in the subways to a universally acknowledged affordability crisis. He touted his achievements as governor, including the much-lauded renovation of LaGuardia Airport and the opening of the Second Avenue subway line.

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Cuomo served as secretary of the Department of Housing and Urban Development under former President Bill Clinton and New York state attorney general. He served nearly three terms as governor before resigning amid a string of allegations of sexual harassment. Cuomo denies the allegations. Clinton endorsed Cuomo late in the race.

If elected, Mamdani would be New York’s youngest mayor in a century, its first Muslim mayor and the first person of South Asian descent to lead the city. He rose in the polls from virtual obscurity thanks to extensive social media outreach, a sophisticated volunteer network, massive donor support and direct mail that resonated with young and progressive voters.

AOC, Sanders

Mamdani, who was first elected to his seat in 2020, was backed by the New York City branch of the Democratic Socialists of America, US Representative Alexandria Ocasio-Cortez and Vermont Senator Bernie Sanders.

Both congratulated him after Cuomo conceded, with Sanders praising his grassroots campaign and Ocasio-Cortez slamming the money that fueled Cuomo’s candidacy.

“Billionaires and lobbyists poured millions against you and our public finance system. And you won,” she said on X.

Mamdani has vowed to freeze rents and make city buses free by raising the state corporate tax rate and imposing a new 2% income tax on city residents who earn more than $1 million a year. The moves would require state approval.

Cuomo has said Mamdani’s plans would cause an exodus of wealthy residents to states like Florida and Texas.

“You elect a socialist who tries to give everything away free, doubles the taxes on the wealthy, and the wealthy say, ‘That’s it, I’m gone,’” Cuomo said in an interview on Bloomberg Radio on June 9.

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Mamdani, an activist for Palestinian causes, has also faced questions over his ability to lead the largest population of Jews outside of Israel. He has refused to say that he supports Israel’s right to exist as a Jewish state, and the US Holocaust Memorial Museum issued a statement condemning Mamdani’s defense of the use of the phrase “globalize the intifada,” a reference to the armed Palestinian uprisings against Israel.

The high stakes of the race — and the ideological gulf between the leading candidates — are reflected in the money. A super PAC backing Cuomo, Fix the City, raised nearly $25 million from finance and real estate billionaires including Michael R. Bloomberg, the founder and majority owner of Bloomberg News parent Bloomberg LP, as well as Bill Ackman, Daniel Loeb and Steven Roth. Home Depot Inc. co-founder Ken Langone and delivery app DoorDash Inc. have also contributed.

The PAC’s effort is the single largest independent expenditure in a city election in the 15 years since the Supreme Court paved the way for virtually unlimited outside spending.

The number of candidates swelled in the months after news broke in 2023 of a federal corruption investigation into Adams, who became the first sitting mayor in the city’s modern history to be indicted on federal charges. The Trump administration ordered those charges dismissed earlier this year.

--With assistance from Raeedah Wahid and Jennah Haque.

(Updates with Cuomo statement in sixth paragraph)