[13][14] With remaining votes still to be counted, she called her win over incumbent Mayor Felipe Alessandri (RN) in the Plaza de Armas past 1 AM of 17 May 2021 amidst chants of "Irací, el otro no".

[15][16] In a 2021 interview with BBC following her victory, Hassler identified ending food insecurity and discrimination against migrants in Santiago as top priorities of her incoming administration.

[17] Hassler was joined by Mayor of Recoleta and 2021 presidential candidate Daniel Jadue, a fellow communist, in a tour of the Barrio Lastarria.

[19] According to El País, Hassler has named U.S. Representative Alexandria Ocasio-Cortez, Mayor of Barcelona Ada Colau, and late Chilean communist leader Gladys Marín as left-wing women in politics she admires.

[5] In 2024 Chilean municipal elections, she lost the re-election of Santiago, defeated by Mario Desbordes (RN) who got over 22% of more votes than Hassler.