Globo News said that with 92.53 percent of the votes counted by the Supreme Electoral Tribunal in the runoff election, Rousseff, 62, had 55.43 percent of the vote to 44.57 percent for Jose Serra, the 68-year-old leader of the Social Democracy Party and former governor of Sao Paulo.
Rousseff had been energy secretary under outgoing President Luiz Inacio Lula da Silva and was widely seen as his political right hand, groomed to be his successor, The New York Times reported. Polls throughout the week had given Rousseff a minimum 10-point lead over Serra, the Times said.
Before the election's outcome, Rubens Barbosa, Brazil's former ambassador to London and Washington, told the newspaper Rousseff isn't likely to wade into the international arena like her effusive former boss.
"Dilma isn't interested in international prestige; she doesn't care if she is seen as a great world leader," Barbosa said. "In the first few years of her administration she is going to concentrate more on domestic and economic policy, and less on taking the lead in international relations."