A defiant Dilma Rousseff called the Senate vote to suspend her as president of Brazil "a coup" by political opponents and vowed to continue to fight her removal from office.
"When an elected president is suspended because of a crime I haven't committed, the name we give it is not impeachment, but a coup," said Rousseff, flanked by supporters, in an address to the nation on Thursday.
"They tried to take by force what they didn't get in votes," she said, slamming the impeachment process as "a judicial farce, a political farce."
Senators voted overwhelmingly in favour of suspending Rousseff from her duties for 180 days and subjecting her to an impeachment trial on charges of budget irregularities.
The 55-22 vote came after a marathon 20-hour debate at the National Congress in the capital, Brasilia.
During the next six months, the Senate will investigate the allegations against her and then conduct another vote.
Impeachment appears likely as a two-thirds majority is needed in the vote to permanently remove her from office. That number was exceeded in the vote on Thursday, even though a simple majority of Senators was all that was required to suspend her.
Rousseff is accused of tampering with figures to disguise the size of Brazil's budget deficit during her 2014 re-election campaign. She has denied any wrongdoing.
Her suspension ends 13 years of rule by the leftist Workers' Party, which has become increasingly unpopular for its handling of the battered economy and its connection to a massive corruption scandal involving the state-run oil company, Petrobras.
Vice President Michel Temer, of the centrist Brazilian Democratic Movement (PMDB), immediately took over as interim president.
Temer has been Rousseff's deputy since she took office in 2011, becoming the first woman to hold the position of president.
But their relationship has deteriorated, with Rousseff now referring to him as a "traitor," and the PMDB withdrawing from the coalition government last month.
Brazil was one of the world's fastest-growing economies until a few years ago, but is now in the midst of one its worst recessions in decades. Some 11 million Brazilians cannot find a job.
Temer, who is perceived as more market-friendly, has called for investor calm. He says he will push for more privatizations, reduce the number of public employees and get the budget deficit under control.
He said he wants to slim down the number of cabinet positions, which are seen as a breeding ground for corruption, and make appointments from all political parties except Rousseff's Workers' Party.
Bitter political rival Eduardo Cunha, who was the president of Brazil's lower house, launched the process to impeach Rousseff in December. The chamber voted in favour of her impeachment in April, sending the issue to the Senate upper chamber.
Cunha was suspended last week on allegations he was obstructing a corruption investigation against himself.
In a last-ditch effort to save her presidency, Rousseff appealed to the Supreme Court this week to block the Senate vote, arguing that Cunha had abused his position of power to seek "revenge."
The court rejected her appeal.
Mass street protests broke out in the country last year, reflecting the anger at the government's inability to improve economic conditions and the corruption scandals that have left around 60 per cent of the 594 members in the National Congress under investigation.
The biggest of all the scandals involves state-run Petrobras. Bribes totaling billions of dollars are alleged to have been paid in the awarding of dozens of contracts by the oil giant to construction companies. Some of the money was then shared with politicians from several political parties.
Rousseff was chairwoman of the Petrobras board between 2003 and 2010, when the kickback schemes were said to have taken place.
She denies having had any knowledge of wrongdoing and has not been charged in the case. She has been mired in the scandal, however, which has helped to drive her popularity rating down to around its current 14 per cent.
"Destiny has always thrown several challenges at me. Great challenges. Some of them seemed unbearable. However I was able to overcome them," she said in her address.
She ended by calling on Brazilians "to say no to the coup."
A long-time left-wing activist who trained as a guerrilla in her youth in order to fight the military dictatorship, Rousseff was elected president in 2010 and was narrowly re-elected to another four-year term in 2014.
In August, hundreds of thousands of athletes, spectators and media will descend on Brazil for the Olympics, a high-profile showcase for the country.
Rousseff ignited the Olympic flame in Brazil's capital last week, kicking off a cross-country torch relay to build enthusiasm for the games.
Intended to be a highlight of her presidency, Rousseff will now watch the Olympics from the sidelines. Temer will open the games on August 5.
The last time Brazil's Senate pressed impeachment proceedings against a president was in 1992. Fernando Affonso Collor de Mello resigned before the trial got under way. He now serves as a senator.