Luiz Inácio Lula da Silva won Brazil's runoff after trailing in the first round, adding 10m votes, with Amazon deforestation policy at stake in his term.
Luiz Inácio Lula da Silva takes 51.79% of the second round to win a fourth term, while Flávio Bolsonaro refuses to recognise the result and calls for annulment.
Brazil's run-off pits Lula against Flávio Bolsonaro after former industrial cities like Osasco swung right, with 33 million abstentions in the first round.
US Senator Bernie Sanders and 11 Democratic lawmakers ask Meta's Mark Zuckerberg to explain alleged unequal treatment of the Lula and Bolsonaro campaigns.
Brazilians vote on 4 October in a presidential election polls call neck and neck between incumbent Luiz Inácio Lula da Silva and senator Flávio Bolsonaro.