Chilean President-elect Gabriel Boric has met with outgoing President Sebastian Pinera in Santiago, just hours after the left-wing candidate’s historic election victory.

The 35-year-old former student activist is set to become the South American nation’s youngest-ever president after he secured 56 percent support to defeat his far-right rival Jose Antonio Kast in Sunday’s runoff.

Nearly 56 percent of eligible voters cast a ballot – the highest rate since voting stopped being mandatory in Chile in 2012.

In a tweet on Monday afternoon, Boric said he was visiting the presidential palace in Santiago at the invitation of Pinera, who will be stepping down in March and earlier offered Boric his government’s full support during the three-month transition.

On Monday, workers with a banner reading, "Hope won over fear. Civil servants welcome you president”, met Boric at La Moneda ahead of his sit-down with Pinera.

"When I was in front of Salvador Allende’s bust, I thought about those who, like him, came before us,” Boric wrote on Twitter, referring to the ex-Chilean president whose government was overthrown in a US-backed coup in 1973.

General Augusto Pinochet then took power, and thousands of Chileans were disappeared, tortured and killed during the ensuing dictatorship, which lasted until 1990 and whose legacy hung over the recent Chilean vote.

"His [Allende’s] dreams of a better Chile are what we will continue to build together,” Boric said.

Al Jazeera’s Latin America editor Lucia Newman, reporting from Santiago, said Boric took time to greet his supporters outside the presidential palace before his meeting with Pinera. "He took selfies with them, signed autographs, basically sending the message that they – the common man and woman – are going to be his priority above everything else,” Newman said.

Boric handily defeated by more than 10 points his presidential opponent, Kast, a far-right former congressman who has held Pinochet in high esteem – a position that raised concerns among relatives of the victims of the 1973-1990 dictatorship.

Kast, whose campaign also fuelled fears among Chilean women and members of the LGBTQ community, immediately conceded defeat on Sunday, tweeting a photo of himself on the phone congratulating his opponent on his "grand triumph”.

He then later travelled personally to Boric’s campaign headquarters to meet with him.

"It’s impossible not to be impressed by the historic turnout, the willingness of Kast to concede and congratulate his opponent even before final results were in, and the generous words of President Pinera,” said Cynthia Arnson, head of the Latin America program at the Wilson Center in Washington.

"Chilean democracy won today, for sure,” she said.

The streets of Santiago and other cities erupted in overnight celebrations at Boric’s victory, which closed a polarising runoff race.

Tens of thousands of people took to the streets, honking car horns in approval, brandishing pro-Boric placards, waving the rainbow LGBTQ flag and shouting: "Viva Chile!” Fireworks lit the skies for hours on end.

In his first official address on Sunday, Boric pledged to "expand social rights” in the country, but to do so with "fiscal responsibility”.

"We will do it protecting our macro-economy, we will do it well … to improve pensions and health care,” Boric said.

Many Chileans had to tap into their pensions amid a coronavirus-related economic downturn earlier this year, while some of the nation’s poorest citizens were hard-hit by lockdowns and other restrictions meant to curb the spread of the virus.

Al Jazeera’s Newman said that particularly after his address to the nation on Sunday night, Boric has made "a very good impression” so far on people in Chile, including those who opposed his candidacy.

"It was a reassuring speech. It was one that really addressed those who had opposed him, not just those who have supported his policies all along, and he sounded very, very moderate and conciliatory,” she reported.

Chile also is going through profound change after voting overwhelmingly last year in favour of replacing the Pinochet-era constitution. The referendum was in response to mass protests in 2019 demanding structural social change.

The drafting process, which is in the hands of a largely left-leaning body elected in May, must yield a constitution for approval next year, on the new president’s watch.