Brazilian President Luiz Inacio Lula da Silva secured a fourth nonconsecutive term after defeating Senator Flavio Bolsonaro in Sunday's presidential runoff, while the defeated candidate vowed to challenge the result in court.
With nearly all polling stations counted, Lula won 51.76% of valid votes, compared with Bolsonaro's 48.24%, according to the Superior Electoral Court (TSE). The margin exceeded 4 million votes.
Bolsonaro, the 45-year-old eldest son of former President Jair Bolsonaro, announced late Sunday that his legal team would petition to annul the election, setting up a potential legal battle over the outcome.
Speaking to supporters after the TSE declared Lula the winner, Bolsonaro launched a sharp attack on the Federal Supreme Court (STF), accusing it of changing the rules of the election through a last-minute decision to extend voting hours nationwide.
"We will engage our legal team and seek to have these elections annulled," Bolsonaro said. "I will not accept that the rules of the game have been arbitrarily changed—once again—by Lula’s friends on the Federal Supreme Court."
His criticism focused on STF Justice Cristiano Zanin, who ordered polling stations to remain open until 7:00 p.m. Brasília time following emergency petitions citing transport blockades and severe weather.
Bolsonaro also pointed to Zanin's previous role as Lula's personal defense lawyer before his appointment to the high court.
The Liberal Party (PL) candidate's move threatened to open a legal fight in Brasília as electoral authorities prepared to certify the final results.
Lula's victory marked a first since Brazil adopted its two-round presidential election system in 1989, making him the first candidate to win the runoff after finishing second in the opening round.
In the Oct. 4 first round, Bolsonaro took 47.03% of valid votes, ahead of Lula's 45.16%. The result set off three weeks of campaigning across Latin America's largest country before Lula turned the race around.
The lead changed hands several times during the early stages of Sunday's count before Lula pulled ahead as more ballots came in, including from urban centers and the heavily populated Northeast.
The result also dealt a setback to the Bolsonaro family, which had sought to return to the presidency through Flavio, a senator and the eldest son of the former president.
Lula previously governed Brazil from 2003 to 2010 before returning to office after winning the 2022 election. He was due to begin his fourth, nonconsecutive term on Jan. 5, 2027.