Brazilian President Dilma Rousseff and her pro-business Social Democrat challenger, Aecio Neves, are headed to an October 26 runoff election.
Rousseff, a leftist seeking a second four-year term, came in first in Sunday's nationwide voting with 42 percent, but was forced into the runoff because she failed to win a majority.
Neves had 34 percent, besting the third-place finisher, former environment minister Marina Silva.
Rousseff had the support of Brazil's working class, thanks to generous social welfare programs initiated during the two terms of her hugely popular predecessor and political godfather, Luiz Inacio Lula da Silva.
She told her supporters at a rally she intends to continue looking to change the country.
"I strongly feel like receiving a message from them (the voters), a simple message, a message that says that I must continue leading and that I must continue to fight together with every voter, to change Brazil," Rousseff said.
Call for unity
Neves called for unity behind his candidacy.
"It's time to unite forces. My candidacy is no longer that of a political party nor candidacy for an alliance," Neves said.
"It is more pure feeling than that which comes from all the Brazilians who are able to feel angry but also to dream. So let us believe, as I always have, that it's possible to give Brazil a government that unites decency and efficiency," he said.
The runoff candidates are from Brazil's two most powerful parties, Rousseff's Workers' Party and Neves's Social Democratic Party.