Claudia Sheinbaum has been elected as Mexico’s first woman president in an historic landslide win.

Mexico’s official electoral authority said preliminary results showed the 61-year-old former mayor of Mexico City winning between 58% and 60% of the vote in Sunday’s election.

That gives her a lead of almost 30 percentage points over her main rival, businesswoman Xóchitl Gálvez.

Ms Sheinbaum will replace her mentor, outgoing President Andrés Manuel López Obrador, on 1 October. Ms Sheinbaum, a former energy scientist, has promised continuity, saying that she will continue to build on the “advances” made by Mr López Obrador.

In her victory speech, she told voters: “I won’t fail you.” Her supporters are celebrating at the Zócalo, Mexico City’s main square, waving banners reading “Claudia Sheinbaum, president”.

Prior to running for president, Ms Sheinbaum was mayor of Mexico City, one of the most influential political positions in the country and one that is seen as paving the way for the presidency.

She spent years at a renown research lab in California studying Mexican energy consumption patterns and became an expert on climate change.

That experience and her student activism eventually earned her the position of secretary of the environment for Mexico City at the time when Andrés Manuel López Obrador was mayor of the capital.

In 2018 she became the first female mayor of Mexico City, a post she held until 2023, when she stepped down to run for president.

The election, which pitted Ms Sheinbaum against Ms Gálvez, has been described as a sea change for women in Mexico. Edelmira Montiel, 87, said that she was grateful to be alive to see a woman elected to the top office.

“Before, we couldn’t even vote, and when you could, it was to vote for the person your husband told you to vote for. Thank God that has changed and I get to live it,” she told Reuters news agency, referring to the fact that women were only allowed to vote in national elections in 1953.