LIVE: Voting is underway across Brazil in a tight presidential race between Lula and Bolsonaro.
Brazil's 158 million voters are deciding between left-wing President Luiz Inacio Lula da Silva and right-wing challenger Senator Flavio Bolsonaro - the son of former president and Trump ally Jair Bolsonaro - after a highly charged round-robin campaign period, with the candidates in a dead heat in the polls.