"The pandemic has put the brakes on the trend towards anti-politics and rejection of traditional parties for being corrupt," said Creomar de Souza, head of Brasilia-based consultancy Dharma Political Risk and Strategy.

"Voters understood that the politicians elected with Bolsonaro in 2018 are flawed and they want to see public services improve," he added.

The results are a setback for Bolsonaro and indicate that the wave of anti-establishment sentiment that got him elected in 2018 following the widespread political corruption uncovered by the Car Wash graft investigation may have subsided.

As voters look to traditional parties, like the DEM and the Brazilian Social Democratic Party (PSDB), which is leading the race for Sao Paulo mayor, Bolsonaro appears vulnerable because he has no party.