Zohran Mamdani has won New York City’s Democratic mayoral primary. A new vote count Tuesday under the city’s ranked choice voting system confirmed the progressive legislator’s stunning upset of former Gov.

Mr. Mamdani roundly defeated Andrew M. Cuomo in the Democratic contest, widening his primary-night lead by a significant margin once ranked-choice tabulations were run.

The state representative initially seemed a long shot but managed to close the gap against disgraced former Gov. Andrew Cuomo.