Quaest Poll: Flávio Bolsonaro Edges Lula 42–41 in Runoff as Gap Halves
Key Facts
—The runoff — Quaest’s Monday release puts Flávio Bolsonaro at 42 percent and President Lula at 41 percent in a second-round simulation — a technical tie, with the gap halved from two points to one in a week.
—The first round — Lula leads 37 percent to 33 percent, followed by Augusto Cury at 6 percent, Ronaldo Caiado at 4 percent, Renan Santos at 3 percent and Romeu Zema at 1 percent.
—The method — Quaest heard 2,004 voters between 17 and 20 September 2026. The margin of error is two percentage points; the survey is registered with the electoral court under protocol BR-06004/2026.
—The split — Released the same day, BTG Pactual/Nexus shows the opposite one-point runoff: Lula 46 percent, Flávio Bolsonaro 45 percent. Same weekend, opposite leaders — the race is a statistical coin flip.
Twelve days before Brazil votes, the two freshest national polls agree on everything except who is winning. Quaest’s Monday round gives Flávio Bolsonaro a one-point runoff edge; BTG Pactual/Nexus, fielded the same weekend, gives Lula a one-point edge. Both gaps sit inside the margin of error — and that, for now, is the result.
What Quaest Published on Monday
Quaest released its latest national poll on Monday, 21 September 2026, commissioned by Globo. Interviewers heard 2,004 voters between 17 and 20 September. The margin of error is two percentage points, and the survey is registered with the Superior Electoral Court (TSE) under protocol BR-06004/2026.
In the runoff simulation, Senator Flávio Bolsonaro (PL) reaches 42 percent against President Luiz Inácio Lula da Silva’s (PT) 41 percent. A week earlier the same series showed 42 to 40 — so the gap has narrowed from two points to one, firmly inside the margin of error. Blank and spoiled ballots account for 14 percent of responses, and 3 percent of voters remain undecided.
The first-round scenario keeps Lula in front, 37 percent to 33 percent. Writer Augusto Cury (Avante) holds third place at 6 percent, followed by Ronaldo Caiado (PSD) at 4 percent, Renan Santos (Missão) at 3 percent and Romeu Zema (Novo) at 1 percent.
Quaest also tested the other matchups — and only Flávio Bolsonaro holds Lula below a clear lead. The president beats Caiado 41 to 39, Cury 39 to 35, Renan Santos 41 to 38 and Zema 46 to 32 in hypothetical runoffs.
The Other Monday Poll Points the Other Way
BTG Pactual’s Nexus institute released its fifteenth tracking wave the same day. Fielded 18 to 20 September with 2,006 telephone interviews, it shows the mirror image: Lula 46 percent, Flávio Bolsonaro 45 percent in the runoff — also a one-point, inside-the-margin gap. In its first round, Lula stands at 40 percent and Flávio at 37, with Cury at 6 percent and Caiado at 5. Nexus also reports that 84 percent of voters say their choice is final. The Rio Times covered that survey in detail here.
Read together, the two freshest rounds say the same thing by disagreeing: neither candidate can claim a lead. UOL’s poll aggregator, which averages all registered institutes, puts the runoff at 44.3 percent for Lula and 44.1 percent for Flávio Bolsonaro.
The picture also tempers Sunday’s Veritá release, which showed Flávio ahead in both rounds — 38.9 to 38.4 in the first round and 48.5 to 43.1 in the runoff. Veritá’s registered national poll was fielded 1 to 4 September, two weeks before the Quaest and Nexus rounds, before the mid-September escalation in Brasília had fully played out. The Rio Times covered the Veritá numbers here.
How the Race Reads Twelve Days Out
Every active institute now agrees on the shape of the first round: Lula leads, by somewhere between three and five points, with Flávio Bolsonaro second and Cury a distant third in single digits. The disagreement is entirely about the runoff — and it splits by institute, not by trend. Quaest, AtlasIntel, Gerp and Veritá show the challenger numerically ahead; Datafolha and BTG Pactual/Nexus hold Lula in front. All but Veritá’s outlier sit inside their own error bands.
The first round is on Sunday, 4 October 2026. A candidate needs more than half of valid votes to win outright; otherwise the top two meet on 25 October. Every Brazilian presidential election since 2002 has gone to a runoff, and no institute currently measures anyone near a first-round majority. The Rio Times tracks every registered survey in its Brazil election polls tracker.
What It Means for Expats and Investors
For markets, a coin-flip race twelve days out means volatility is the base case. Trading desks price an average of institutes, and the spread between Datafolha, Quaest and Veritá is wide enough to move the real and the Bovespa on every release day. With free TV advertising running and the campaign’s final stretch ahead, expect each new poll to be traded as an event in itself.
What We Could Not Confirm
Whether Quaest’s first-round sub-numbers below Cury — Caiado, Santos and Zema — shifted from the previous wave; the institute’s Monday release emphasized the runoff and the top three. How the 84 percent “decided vote” figure in the Nexus survey compares with earlier waves in its own series. And whether PoderData’s weekly round, expected but not confirmed for this week, will break the one-point symmetry.
Frequently Asked Questions
What does the new Quaest poll say about Lula versus Flávio Bolsonaro?
Quaest’s poll released on 21 September 2026 shows Flávio Bolsonaro at 42 percent and Lula at 41 percent in a runoff — a technical tie inside the two-point margin of error. In the first round, Lula leads 37 percent to 33 percent.
How was the Quaest poll conducted?
Quaest interviewed 2,004 voters between 17 and 20 September 2026, with a two-point margin of error and 95 percent confidence. The survey is registered with the electoral court under protocol BR-06004/2026.
Do other pollsters agree with Quaest?
Not on the leader. BTG Pactual/Nexus, fielded the same weekend, shows the opposite one-point runoff: Lula 46, Flávio 45. Datafolha holds Lula ahead 46–44, while AtlasIntel, Gerp and Veritá show Flávio numerically in front. UOL’s aggregator averages the runoff at 44.3 to 44.1 for Lula.
When is the Brazilian election?
The first round takes place on Sunday, 4 October 2026. If no candidate wins a majority of valid votes, the top two meet in a runoff on Sunday, 25 October 2026.
Sources: Quaest national poll released 21 September 2026 via G1/Globo, Estadão and JOTA (TSE registration BR-06004/2026, fieldwork 17–20 September, 2,004 respondents, ±2pp); BTG Pactual/Nexus fifteenth wave via Nexus (fieldwork 18–20 September, 2,006 CATI interviews, ±2pp); UOL poll aggregator, 21 September 2026.
More: Brazil election 2026 coverage from The Rio Times.
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