(CNN) -- Brazil's new president-elect vowed to continue her predecessor's move to fight against inequality and promote human rights and fight poverty in her victory speech Sunday night.

"My mission is to eradicate poverty," Dilma Rousseff said after the country's Supreme Electoral Tribunal declared her the winner in Sunday's runoff election.

As the nation's first woman to hold the office, Rousseff said she has a mission to fight for more gender equality in Brazil.

"I hope the fathers and mothers of little girls will look at them and say yes, women can."

Rousseff -- President Luiz Inacio da Silva's right-hand woman -- has served as his chief of staff.

Previously, as energy minister, she claims to have helped turn Brazil into one of the world's leading energy giants.

A left-wing guerrilla fighter during the military dictatorship rule in the 1960s, Rousseff said during a congressional hearing that she was "barbarically tortured" after she was charged with subversion by the military regime.

Her opponent, Jose Serra, also suffered persecution during Brazil's military rule and was forced into exile during the 1960s.

A centrist politician, he served as health minister during Fernando Henrique Cardoso's government. He recently left his job as governor of Brazil's richest state, Sao Paulo, to run for presidency.

Millions of voters lined up across Brazil's vast territory to vote in the heated runoff.

In 60 Brazilian cities, voters used their thumbs instead of ballots on a newly launched biometric system, where voters scan their fingers to log in and vote.

TSE officials said all regions, however remote, will have the ubiquitous electronic voting machine. In indigenous areas in the Amazon, these voting machines were delivered by boats and helicopters. It costs the state of Amazonas 5 million reais. (U.S. $3 million) to place the voting machines.

One of the most challenging trajectories, officials said, is the one to Sao Gabriel da Cachoeira, a densly-forested area in the Amazon.

"There, our electronic machines first leave Manaus by plane," said Pedro Batista, TSE Director for the Amazon.

"It's loaded onto a helicopter, and then travels by boat before being carried on some one's back for a long walk to a remote village," he said.

In Sao Paulo, Brazil's largest city, voters faced heavy rains and threats of flooding.