While electoral authorities reported no major fraud or violence in the country, security was tightened in Rio de Janeiro where drug gangs and militias had threatened some candidates during the campaign.
Seven people were also reportedly shot dead in isolated incidents and more than 800 arrested - including 101 candidates.
The Superior Electoral Court said after voting ended that 2,511 polling violation complaints had been registered during the day, resulting in 808 arrests.
Many of the 101 candidates apprehended were running in the largely rural states of Minas Gerais, Espiritu Santo and Mato Grosso, it said.
A 30-year-old unidentified man was also shot and wounded in the leg by guards when he ignored warnings and tried to enter Lula's official residence in the capital Brasilia, officials said.
Lula was not there at the time, having gone to his southwestern home town of Sao Bernardo do Campo to vote.