Luiz Inacio Lula da Silva, icon of the Brazilian left, won 48% of the vote, ahead of the outgoing far-right president, 43%, or about 6 million votes apart, according to almost final official results.
The polls were seriously mistaken, which promised Lula a lead of 14 points in the voting intentions (50% against 36%) and did not exclude a victory in the 1st round.
"I can tell you that we are going to win this election. It's just an extension," the old lion of Brazilian politics told his supporters late Sunday evening, still visibly affected by this electoral disappointment.
Lula promised "more trips and other meetings" to meet Brazilians to win a third term on October 30, because "we will have to convince Brazilian society".
"Tomorrow I start campaigning. If I had won in the first round, I would have taken three days off and gone on my honeymoon," said Lula, who married his 3rd wife, "Janja". in May.
The general elections organized in Brazil on Sunday were also a success for the Bolsonarists, many of whom were elected, deputies or governors, in particular former ministers of Jair Bolsonaro, in the Senate in particular.
"We are going to see a radically polarized 2nd round", predicts Bruna Santos, of the Brazil institute, when Brazil is already very fractured after four years of Bolsonaro's mandate.
For Paulo Calmon, a political scientist from the University of Brasilia, "the race will be even more open and promises a fierce dispute". For him, "Bolsonaro maintains all his chances of re-election".
- Trouble in the streets -
Lula will also have to change strategy after having made the mistake, before the first round, of campaigning "focused only on the achievements of these two previous mandates" (2003-2010) and he will have to "present projects for the future ".
"The game for the second round is going to be tough", adds Marco Antonio Teixeira, of the Getulio Vargas Foundation (FGV): "there is only a five point gap" between Lula and Bolsonaro, "we are going to experience a period very tense."
Bolsonaro's performance should "boost him," says Inter-American Dialogue analyst Michael Shifter.
Lula's relative setback gives him "an extra month to cause unrest in the streets," said Guilherme Casaroes of the Getulio Vargas Foundation.
He too considers that "Lula's chances of being elected are much lower".
"We cannot exclude that Bolsonaro galvanizes his base and encourages him to chase Lula supporters," said Mr. Shifter.
Between the two camps "there is a lot of resentment, hatred and it would not be surprising if this led to unrest", while the campaign has already experienced violence.
Lula supporters have often indicated that they have not worn the red color of the Workers' Party (PT) for fear of attacks from Bolsonarists.
- Hatred of polls -
Arrived in 3rd and 4th position in the presidential election, Simone Tebet (MDB from the center right) who obtained 4% and Ciro Gomes (PDT, center left) 3% will be very courted.
"The voters of Simone Tebet and Ciro Gomes, about eight million people, will decide who will be the next president," said Bruna Santos.
Finally, the first round will have confirmed Jair Bolsonaro in his hatred of the polls, which placed him far behind Lula for weeks.
"We made the polls lie!" exulted Sunday evening the populist president, who says he prefers to take the pulse of Brazilians in the street, during his big meetings or during walkabouts.
For Guilherme Casaroes, of the FGV, "the polling institutes, which have given inconsistent projections for both the presidential elections and those of the States will have to reinvent themselves".