Jair Bolsonaro, a pro-dictatorship former army captain, secured almost 50m votes in the first round of Brazil's presidential election on Sunday - about 46% of the total and just short of the outright majority needed to claim victory.
With 92 per cent of votes counted, Mt Bolsonaro had received 47 per cent of valid votes, far ahead of former Sao Paulo mayor and leftist rival Fernando Haddad's 28 per cent, electoral court TSE reported.
Monica de Bolle, the director of Latin American studies at Johns Hopkins University, said she expected Bolsonaro to come under heavy fire from Haddad and other defeated presidential candidates, above all for his disdain for democracy.
Brazilians choose among 13 candidates for president Sunday in one of the most unpredictable and divisive elections in decades. In a broadside against Bolsonaro, who frequently talks about liberalizing gun laws, Haddad said: "We don't carry guns". He reportedly said to a female congresswoman, publicly, that he would not sexually assault her because she was not worthy of him.
Meanwhile, true to the Workers' Party's leftist roots, Haddad has promised to fight long-standing inequalities, scrap a major labor reform passed a year ago and invest more in education.
"Bolsonaro has been so successful because he was the first to realize that this would be a 'change election, ' and he has systematically adopted an anti-system rhetoric, allowing him to mobilize people who wanted a more radical change", Prof.
Brian Winter, the editor-in-chief of Americas Quarterly magazine, said the results underscored "the total disappearance of the Brazilian centre" and that Bolsonaro seemed nearly certain to glide to victory.
He was unable to campaign in person or participate in debates as he underwent surgeries during a three-week hospital stay - instead he used social media to communicate with the electorate. The two men will face an Oct 28 runoff.
Brazil's currency, the real BRBY, gained 2 percent to 3.78 to the dollar, the strongest since August, while yields on interest rate futures 0#DIJ: fell sharply.
They underestimated Bolsonaro and overestimated the traditional parties as well as - most crucially - the effectiveness of television advertising in the election.
Senna said he was anxious that Bolsonaro's presidential rivals would gang up on him and back Haddad in the runoff.
Indicators from Sunday's results, aside from the 49 million votes Bolsonaro picked up, suggest that is the case and that prevailing public sentiment points towards him succeeding in the second round.
Supporters of presidential frontrunner Jair Bolsonaro of the Social Liberal Party, celebrate as they wait for the first results of the vote counting. Bolsonaro has been endorsed by the fifth-place finisher, potentially handing him nearly half the votes he needs for a win.
Haddad may yet gain the backing of other candidates in the race, but that might just feed Bolsonaro's criticism that traditional politicians are only interested in protecting their own. They sent precisely the two candidates who most polarize the population to a runoff election, thus aggravating the country's problems still further.