SAO PAULO, July 29 (Reuters) - Brazilian President Luiz Inacio Lula da Silva leads a potential second-round vote in the October presidential election against opposition Senator Flavio Bolsonaro, an AtlasIntel/Bloomberg poll showed on Wednesday.
Lula would receive 49.2% of votes in a runoff, compared with 42.9% for Flavio Bolsonaro, the son of ex-President Jair Bolsonaro, the poll showed. In June, Lula had 48.8% of votes vs Bolsonaro's 42.3%.
Undecided voters and those intending to cast blank or spoiled ballots fell to 7.9% from 8.9% in June.
In a first-round scenario, Lula leads with 44.9% of the vote, followed by Senator Bolsonaro at 35.8%, Renan Santos at 7.8%, Ronaldo Caiado at 3.1%, and Romeu Zema at 2.8%.
The poll surveyed 5,021 people between July 22 and 27; it has a margin of error of one percentage point in either direction.
(Reporting by Andre Romani, Editing by Natalia Siniawski)