RIO DE JANEIRO, Brazil (AFP) — The result of Brazil's first round of presidential voting on Sunday seems to bear out claims by incumbent President Jair Bolsonaro that surveys were wrong in predicting his loss.

Bolsonaro's rival, ex-president and frontrunner Luiz Inacio Lula da Silva, 76, failed to garner the 50 percent of votes plus one needed to avoid a 30 October runoff against the far-right Bolsonaro, 67.

Lula got 48.4 percent of the vote in Sunday's first round, followed by Bolsonaro with a much closer-than-expected 43.2 percent that seemed to signal a high level of enthusiasm for his conservative brand of "God, country and family" politics.

Lula had gone into Sunday's first round with 50 percent of polled voter intention, and Bolsonaro with 36 percent.

Bolsonaro has repeatedly sought to cast doubt on Brazil's electronic voting system and has questioned the validity of opinion polls that have consistently placed him a distant second.

Now, with real-life results seeming to bear out his claims, "more people… may believe in what Bolsonaro is saying," Leonardo Paz, Brazil consultant for the International Crisis Group, told AFP.

Bolsonaro "will be very emboldened," by Sunday's electoral performance, Michael Shifter of the Inter-American Dialogue think tank said.

"It will give him some momentum because he's beaten the expectations… He will play on that the experts were wrong: 'I've got the momentum and I'll defy expectations again in the second round.'"

Late Sunday, Bolsonaro proclaimed to journalists: "We defeated the opinion polls' lie."

A 'Bolsonarist' wave energized by the first-round results "will boost the president's campaign and may help demobilize the non-convinced voters of Lula."

It also means Lula will have to "court centrists and even conservatives much more aggressively during the next four weeks," the FGV's Oliver Stuenkel said, possibly hurting his standing with more radical leftist supporters.