Leading Latin American leftists have celebrated the thwarting of Javier Milei’s attempt to claim a first-round victory in Argentina’s presidential election after the far-right populist was beaten by his centrist rival Sergio Massa. Milei, an oddball economist who has called climate change a “socialist lie” and the pope “a lefty son of a bitch”, had hoped an explosion of anti-establishment rage would catapult him into the presidency on Sunday as 27 million Argentinians turned out to vote amid the country’s worst economic crisis in decades. But Milei, who was widely regarded as the election frontrunner, was pipped to the post by the Peronist finance minister Massa, who received 36.6% of votes to Milei’s 29.9%. The two men will now face off in a second-round showdown on 19 November. Colombia’s leftist president, Gustavo Petro, led the celebration of Milei’s unexpected setback, which dealt a bitter blow to members of the global far right hoping a Milei victory would allow them to make a powerful show of strength. “Argentina has defeated barbarism,” Petro tweeted. “This is the time of hope.” Brazil’s leftwing president, Luiz Inácio Lula da Silva, also commemorated a result most polls had failed to foresee. “Formidable, my friend,” Lula reportedly wrote in a private message to Massa, according to the Argentinian newspaper Clarín. Lula’s chief foreign policy adviser, Celso Amorim, called the result one of “relief and renewed hope” although he cautioned that “the struggle is not over”. Paulo Pimenta, Lula’s communications minister, tweeted: “Long live democracy!” Milei put a positive spin on his failure to win as he addressed supporters in Buenos Aires on Sunday night, calling his presence in the election runoff “a genuinely historic achievement”. Milei, a television celebrity who only entered politics in 2021, called on all opponents of Massa’s Peronist coalition to unite against what he called the “criminal organization” he blames for triple-digit inflation and plunging 40% of Argentina’s 46 million citizens into poverty. “If we work together, we can win. If we work together, we can recover our country,” insisted Milei, who will hope to lure some of the 6.3 million voters who backed the third-placed candidate, the conservative former security minister Patricia Bullrich. Many of the 2.5 million votes that went to the fourth- and fifth-placed centre-left and leftwing candidates, Juan Schiaretti and Myriam Bregman, are expected to migrate to Massa. As she accepted defeat on Sunday night, Bullrich dropped a strong hint she would endorse Milei, vowing to never be an “accomplice” of the Peronist populists she accused of impoverishing Argentina and producing “the worst government in [its] history”. Prominent members of Latin America’s far right pushed back against the portrayal of Milei’s second-placed finish as a flop. “Milei certainly goes into the second round as favourite,” claimed Eduardo Bolsonaro, the congressman son of the former Brazilian president Jair Bolsonaro, who had flown into Buenos Aires hoping to celebrate a far-right triumph similar to his father’s 2018 election in Brazil. Bolsonaro shared a viral video of one Argentinian casting his vote dressed as a chainsaw – the symbol of Milei’s campaign to cut spending and sever Argentina’s political establishment – as proof that his movement was an unstoppable “phenomenon”. But the frustration of Mileístas was palpable outside the luxury hotel where the self-styled “anarcho-capitalist” had made his campaign headquarters. Crestfallen Milei supporters who had gathered outside the building in anticipation of a first-round win that never came, claimed, without evidence, that the vote had been rigged. “It hurts my soul. I expected he’d win in the first round. I was surprised,” admitted Iván González, a 22-year-old Milei supporter who wore a Donald Trump hat and carried a yellow Gadsden flag – an American-revolution era banner used by the US extreme right and Milei’s movement. González blamed Massa’s “fearmongering” campaign for Sunday’s setback but insisted he had not given up hope of a second-round win. Brian Winter, editor-in-chief of Americas Quarterly, said it was hard to say which of the two candidates was now favourite to become president. Winter attributed Milei’s failure to come out on top to “cold feet” among voters who had too many doubts about his temperament, ability to govern and radical ideas, which include loosening gun laws, questioning the number of people killed during Argentina’s 1976-83 dictatorship and legalizing the sale of human organs. Winter suspected Milei’s campaign had scared off some voters by placing too much emphasis on culture-war issues such as abortion and gun culture and appearing too close to rightwing figures such as Trump and Bolsonaro. “I think the people who put the memes together with Milei, Bolsonaro and Trump didn’t do Milei any favours. That brand of conservatism will get you 30% in Argentina but it’s not going to get you to 50%,” Winter said. “Argentina is not Brazil and Argentina is not Texas … Argentina is not a country where a pro-gun agenda is going to carry the day.” Still, Winter believed Milei still had a path to victory if he could secure the support of influential political figures such as the former conservative president Mauricio Macri and show voters “a somewhat more moderate” face. “[Argentina] is a country where people are just desperate for change – so don’t count Milei out.” Writing on Twitter, the veteran Latin America watcher Michael Reid, wrote: “Either could win but Massa now has an easier path to the presidency than Milei … Milei has lost that most precious political quality, momentum and may find it hard to recover it.”