BUENOS AIRES, Argentina — President Mauricio Macri conceded defeat in Argentina's election on Sunday night, paving the way for the country's Peronist center-left to return to power under Alberto Fernández as frustrated voters rejected the president's handling of a bruising economic crisis that has sunk many into poverty.
The result could rattle financial markets over concerns of a return to the interventionist policies of former President Cristina Fernández de Kirchner, who is Alberto Fernández's vice presidential running mate. Opponents believe that she would be the power behind the throne in a Peronist government — a fear dismissed by the candidates.
Thousands of the two Fernándezes' supporters crowded their campaign headquarters in a jubilant celebration waving sky-blue and white Argentine flags and chanting: "We're coming back! We're coming back!"
"Today, Alberto is the president of all Argentines," said Cristina Fernández, who governed Argentina from 2007 to 2015. "He will have a very hard task ahead of us that will require the cooperation of all Argentines."
She blew kisses at the crowd and thanked supporters who brandished tattoos with her image and the image of her late husband, Néstor Kirchner, who preceded her as president until his death nine years ago.
Alberto Fernández served as chief of staff for Néstor Kirchner from 2003 to 2007 and remained in the position during part of Cristina Fernández's term as president.
On Sunday, he thanked all Argentines, paid homage to Kirchner and said he would need the support of Macri's administration to reconstruct what he called the inherited "ashes" of Argentina.
"The only thing that concerns us is that Argentines stop suffering once and for all," he told the crowd. "We're back, and we're going to be better!"
Earlier in the evening, Macri told disappointed supporters at his headquarters that he had called to congratulate Alberto Fernández and invite him for a breakfast chat Monday at the Pink Presidential Palace.
"We need an orderly transition that will bring tranquility to all Argentines, because the most important thing is the well-being of all Argentines," Macri said.
Authorities said Fernández had 48 percent of the votes, compared to 40.47 percent for Macri, with 95.54 percent of the votes counted. He needs 45 percent support, or 40 percent support with a 10 percentage-point lead, to avoid a runoff on Nov. 24. The result still needed to be confirmed early Monday.
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Macri was elected in 2015 by promising to jump-start the 's economy. Argentines at the time rejected a successor chosen by Cristina Fernández, who, along with her late husband, dominated the political scene for 12 years and rewrote its social contract. But the divisive former leader, who embodies Argentina's enduring cycle of hope and despair, is back.
Juan Jose De Antonio, 46, a supporter, said: "I'm so happy. We were waiting for this change for a long time. We're tired of everything that has been happening.
"Some of us live a different reality from those suffering hunger, but when you have a friend who lost a job, a neighbor who can't make ends meet, it hits you," he said.
Sunday's largely peaceful election was dominated by concerns over rising poverty, a sharp depreciation of the currency and one of the world's highest inflation rates. Voters appeared to have rejected austerity measures that Macri insisted were needed to revive the struggling economy. Many Argentines have taken to the streets frustrated with cuts in subsidies that have led to rises in utilities and transportation costs.
The result also marks a shift leftward for South America, which has seen conservative governments elected in Brazil, Colombia and Chile in recent years. Cristina Fernández was considered part of the "pink tide" of leftist governments that arose in the region in the 1990s and the 2000s.
The Peronists' apparent return to power comes as other governments in the region come under pressure for corruption, inequality and slowing growth, most notably in Chile, which recently saw a protest with more than 1 million participants.
"We Argentines deserve a better country, with work, where we can live peacefully, above all," Antonella Bruna, 32, said as she voted at the medical school of the National University of Rosario, about 180 miles northwest of Buenos Aires.
Macri, the pro-business former mayor of Buenos Aires, retained wide support among the key farming sector in one of the world's top suppliers of grains. But overall frustration over the economy eroded his popularity . It also propelled the candidacy of Alberto Fernández, whose surge has sent jitters in the financial markets.
In Argentina's August party primaries, Macri's surprisingly poor performance caused stocks to plunge, and the peso depreciated on the possibility of a return to Cristina Fernández's interventionist economic policies, analysts said.
Macri's camp tried, but failed to capitalize on that unease, portraying her as a puppet master waiting in the wings.