Senator Flávio Bolsonaro of the right-wing PL party leads President Luiz Inácio Lula da Silva numerically for the first time in a runoff simulation by the BTG/Nexus poll released on Tuesday, September 8. The senator, eldest son of former president Jair Bolsonaro, has 46% of voting intentions against 45% for Lula, of the Workers' Party. The one-point gap sits inside the survey's two-point margin of error, which makes the race a technical tie.

The result reverses the previous round, released on August 31, when Lula had 46% and Flávio 45%. Until now the president had led numerically in every head-to-head test between the two in the series. This was the 13th round, according to news site JOTA.

Cury moves ahead

In another runoff scenario, physician and writer Augusto Cury, of the Avante party, scores 45% against 43% for Lula, also a technical tie. According to Congresso em Foco, the report for this round carries no historical series for that matchup. Blank and spoiled ballots add up to 10%, and 1% of respondents did not know or did not answer.

Cury is the only opponent besides Flávio to sit numerically ahead of the president. Lula leads the three remaining scenarios: 46% to 43% over Ronaldo Caiado (PSD), 47% to 40% over Romeu Zema (Novo) and 47% to 39% over Renan Santos (Missão).

First round and voter certainty

Lula still leads the first-round ballot with 39%, against 35% for Flávio, as reported by Congresso em Foco and JOTA; CNN Brasil reported 34% for the senator. JOTA says the senator rose from 33% and reads the round as "a recovery for Flávio Bolsonaro after a week dominated by news involving the Supreme Federal Court". Cury has 9%, Caiado and Renan Santos have 4% each, and Zema has 1%.

Nexus interviewed 2,002 voters by phone between September 4 and 7. The margin of error is two percentage points, with a 95% confidence level, and the poll is registered with the Superior Electoral Court as BR-06790/2026. Among Lula's voters, 90% say their decision is final; among Flávio's, 84%. For Cury, 58% say they will stick with him and 39% admit they may switch. CNN Brasil also reported rejection of Flávio at 50% and of Lula at 49%.

An earlier Quaest round had already shown the two tied at 41% in a runoff. The first round of Brazil's presidential election is set for October 4, and a runoff, if needed, for October 25.