BRASILIA, Oct. 3 (Xinhua) -- A presidential runoff is inevitable for Brazil as no candidate clinched an absolute majority in the first round of voting, the country's highest court said Sunday night.

Dilma Rousseff, the Brazilian ruling party's candidate, grabbed more than 45 percent of the votes, but still fell short of the 50 percent plus one votes required to avoid a runoff with her second-placed rival Jose Serra on Oct. 31.