SAO PAULO, Oct 3 (Reuters) - A series of polls on Saturday showed Brazilian President Luiz Inacio Lula da Silva slightly ahead of Senator Flavio Bolsonaro before Sunday's first-round vote, and a close race in a likely runoff between the leftist incumbent and his right-wing challenger.
If no candidate wins more than 50% of valid votes -- which exclude blank and null ballots -- on Sunday, the two frontrunners advance to a second-round runoff on October 25.
CNT/MDA POLL
• First round (valid votes): Lula 47.8%, Bolsonaro 42.1%, Augusto Cury 3.6%, Ronaldo Caiado 3.4%, Renan Santos 1.7%, Romeu Zema 0.9%
• Runoff: Lula 47.3%, Bolsonaro 43.1%
• MDA surveyed 2,007 people from September 30 to October 2; margin of error of 2.2 percentage points
DATAFOLHA
• First round (valid votes): Lula 45%, Bolsonaro 42%, Caiado 4%, Santos 3%, Cury 3%, Zema 1%
• Runoff: Lula 47%, Bolsonaro 46%
• Datafolha surveyed 4,006 people from October 2-3; margin of error 2 percentage points
QUAEST POLL
• First round (valid votes): Lula 46%, Bolsonaro 45%, Cury 3%, Santos 3%, Caiado 3%
• Runoff: Bolsonaro 44%, Lula 42%
• Quaest surveyed 3,702 people from October 2-3; margin of error 2 percentage points
ATLASINTEL/BLOOMBERG POLL
• First round (valid votes): Lula 47%, Bolsonaro 44.1%, Santos 4.6%, Cury 2.1%, Caiado 1.4%
• Runoff: Lula 47.6%, Bolsonaro 47.4%
• AtlasIntel surveyed 4,945 people from September 27 to October 2; margin of error 1 percentage point
(Reporting by Eduardo Simoes, Gabriel Araujo, Pedro Fonseca and Alexandre Caverni; Editing by Alison Williams and Chizu Nomiyama)
