A woman will head Mexico's Supreme Court for the first time after Norma Lucia Pina was elected president on Monday amid controversy over plagiarism allegations against a rival candidate.

The 63-year-old constitutional law specialist welcomed the opportunity to "break what seemed like an inaccessible glass ceiling."

Pina, who has defended the right to abortion and pledged to fight gender-based violence, won the votes of six of the 11 Supreme Court judges.

The election to replace Arturo Zaldivar was shaken by accusations that Supreme Court justice Yasmin Esquivel, another hopeful for the post, plagiarized her graduation thesis in 1987.

Esquivel is seen as close to President Andres Manuel Lopez Obrador, who rejected the claims as an attack against him but pledged to recognize the outcome of the vote.

"There's no way we're going to declare war on the judiciary," he said.

Esquivel denied the allegations, prompted by an analysis by a professor at the National Autonomous University of Mexico, and accused another lawyer of copying parts of her thesis.

Local media reported Monday that the Mexico City Prosecutor's Office had cleared Esquivel of plagiarism, though there was no official announcement.