In Brasília, Flavio Bolsonaro watched the count climb past 99% of ballots on Sunday night, holding 47.2% against President Luiz Inácio Lula da Silva's 45%. Across the country in São Paulo, Lula followed the same numbers on a different screen, the gap just wide enough to deny either man the outright majority needed to win in a single round. Brazil's electoral court confirmed what both camps had quietly expected by evening: a runoff on October 25 will decide who leads Latin America's largest democracy.

Neither man hid his surprise, though for different reasons. "Tomorrow we start a new campaign," said Lula, who is bidding for a fourth, non-consecutive term at age 80. "I am very good in the knockout stage." Bolsonaro, seeking to extend the right-wing populist movement his father Jair built, struck a confident tone of his own, saying he was pleased with the real chance that Brazilians would soon give what he called a definitive answer by choosing a modern government.

The result caps a weekend of dueling rallies, including one in São Paulo where organizers said 150,000 Lula supporters gathered as he vowed to defeat the far right. Yet analysts see the broader trend working against him. Fabio de Sá e Silva, a professor of Brazilian studies at the University of Oklahoma, told DW that the real story may not be the runoff itself but a parallel takeover of Congress by the far right, a shift that could hamstring whoever wins the presidency. "He still has a chance, based on the numbers, but the momentum is with the right," de Sá e Silva said of Lula.

With three weeks left before the decisive vote, both campaigns must now persuade a divided electorate stretching from the favelas of Rio de Janeiro to the agribusiness heartlands of Mato Grosso.