Darializa Avila Chevalier, a community organizer backed by New York City’s mayor, has defeated five-term U.S. Rep Adriano Espaillat in a Democratic primary for his congressional seat.

Avila Chevalier was endorsed by Mayor Zohran Mamdani in the primary battle and now advances to the November general election for the district extending in upper Manhattan and the Bronx. Her victory was a test of Mamdani’s political clout for the progressive left in reshaping New York’s congressional delegation.

Avila Chevalier, 32, is a political newcomer. A doctoral student at the City University of New York and a graduate of Columbia University, she had helped organize college campus protests in recent years.