Runoff likely as Brazil goes to polls

About 70 percent say they want things to change, a survey finds

The twists and turns in Brazil's presidential race ended on Sunday, at least for a few hours, as millions of Brazilians cast ballots in an election expected to force a three-week runoff campaign between incumbent Dilma Rousseff and one of her two top challengers.

Rousseff held a commanding lead in all recent opinion polls, with her support rising to 46 percent in a survey released on Saturday. But it was thought unlikely she could push through to win the majority required to avoid a second-round election.