New York City Mayor Zohran Mamdani scored a major political victory Tuesday night as three candidates he endorsed emerged victorious in Democratic congressional primaries, including two races in which sitting members of Congress were defeated.

One of the most closely watched contests saw former New York City Comptroller Brad Lander unseat Rep. Dan Goldman in the 10th Congressional District, which spans portions of lower Manhattan and Brooklyn.

In another upset, Darializa Avila Chevalier defeated Rep. Adriano Espaillat in the 13th Congressional District, covering upper Manhattan and sections of the Bronx.

Meanwhile, Claire Valdez, the third candidate backed by Mamdani, secured the Democratic nomination in the open race for the 7th Congressional District, which includes parts of Brooklyn and Queens. The seat is being vacated by Rep. Nydia Velázquez, who chose not to seek another term.

Chevalier and Valdez also received support from the Democratic Socialists of America, which has played an increasingly influential role in New York City politics.

The victories come roughly a year after the DSA helped propel Mamdani to a stunning upset over former New York Gov. Andrew Cuomo in the Democratic mayoral primary, a victory that reverberated far beyond the city and was followed by a successful general election campaign.

Speaking Tuesday, Mamdani framed the results as part of a broader effort to reshape the Democratic Party.

“It’s not just a question of electing more Democrats. It’s a question of electing better Democrats, ” Mamdani said Tuesday, according to The Associated Press.

He added that the successful candidates share a commitment to prioritizing the concerns of ordinary Americans.

“When I look at these candidacies, I see in them a willingness to also put working people back at the heart of our politics,” Mamdani said.

Another high-profile race unfolded in Manhattan’s 12th Congressional District, where state Assemblyman Micah Lasher won a crowded primary to succeed retiring Rep. Jerry Nadler.

Lasher prevailed over fellow Assemblyman Alex Bores and several other contenders, including Jake Schlossberg, the grandson of President John F. Kennedy.

The race attracted extraordinary outside spending, with two political action committees linked to major artificial intelligence companies pouring a combined $20 million into efforts either supporting or opposing Bores.

Given the overwhelmingly Democratic makeup of the districts involved, the winners of all four primaries are widely expected to prevail in November’s general election and head to Washington next year.