BRASILIA/SAO PAULO/RIO DE JANEIRO—S enator Flavio Bolsonaro held a narrowing lead in the first round of Brazil's presidential election on Sunday, after more than half the votes were counted, with pollster Datafolha projecting that the election would proceed to a second vote. Flavio, the 45-year-old son of former President Jair Bolsonaro who hopes to return his father's right-wing movement to power, was leading leftist President Luiz Inacio Lula da Silva, 80, who is seeking a fourth term, following a campaign dominated by corruption scandals, economic anxiety and accusations of US meddling. With about 65% of votes reported, Flavio led Lula with 49.58% of the votes to the president's 42.25%. A candidate must pass 50% in order to win outright in the first round. The two leading candidates were expected to head into a second round vote, Brazilian pollster Datafolha said. Surveys have shown Lula and Flavio polling roughly even in an October 25 runoff. Early results showed southern states that lean to Bolsonaro reporting faster, while votes from Lula's northeast stronghold are tallied more s