After waiting all night, a vast crowd in Buenos Aires erupted in joyful cries of "Long Live the Pope!" as the new Argentine pontiff on Tuesday received the symbols of papal power.
The well-wishers got an unexpected treat when Pope Francis delivered a special message in Spanish to his countrymen in Buenos Aires.
Before his inauguration mass at the Vatican, he asked Argentines to keep him in their thought and prayers.
"Please do not forget this bishop, who is far but loves you very much. Pray for me," Pope Francis told the crowd, estimated by the archdiocese here to number about 40,000, in a telephone message broadcast on giant TV screens.
Later, the multitude -- which had assembled in the Plaza de Mayo and outside the city's cathedral -- cheered and applauded when the pope received the formal symbols of his office: the papal ring and the pallium, a lambs wool strip of cloth that symbolizes the pope's role as a shepherd.
There were similar outpourings in cities and towns across Argentina as the faithful waved baby blue and white Argentine flags and memorabilia from the San Lorenzo football club that the former cardinal ardently follows.
Throngs of well wishers gathered across the country, from La Quiaca in the far north to Ushuaia at the bottom of the world.
The new pope -- until days ago Cardinal Jorge Mario Bergoglio, Archbishop of Buenos Aires -- regularly said mass at the cathedral on a corner of the Plaza de Mayo. The president's office, the Casa Rosada, is also located on the plaza.
Overnight, Catholic high school students chanted slogans praising Francis, while seminarians and nuns waved white and yellow Vatican flags and placards.
The pontiff's sister, Maria Elena Bergoglio, told reporters she was certain her brother would remain unchanged in his new role.
"Francisco is still Jorge," she told reporters when the ceremony was over.
"He's going to make members of his security detail go crazy, but that's his choice and I like it," she said at the door of her home in the city of Ituzaingo outside Buenos Aires.
The leader of the world's 1.2 billion Roman Catholics was formally inaugurated at a huge open air mass in St Peter's Square in Rome, striking a deep chord with Catholics in Francis's native Argentina.
"This pope has awakened deep emotions within me, not only because he's from Argentina, but because of his warmth as a person," said Celia Farias, 33.
"As a Catholic, it has renewed my faith," she told AFP.
For Andrea Cosentino, a 40 year-old homemaker, Francis's papacy will result in the church "getting close to the common people."
Both women arrived at the Plaza de Mayo armed with folding chairs, signs, jackets for the cold weather, an umbrella "in case it rains" -- and gourds with yerba mate, a traditional Argentine tea that the pope enjoys.
Before traveling to the Vatican for the inauguration ceremony, Buenos Aires Mayor Mauricio Macri ordered the public school system closed for the day.
Some 75 percent of Argentina's 40 million people say they are Catholic, according to church officials.
The faithful here in downtown Buenos Aires were delighted by Francis' comments directed to his compatriots.
"Let there be no hatred, no fighting, put envy aside," the pontiff said in his remarks.
"Do not take out the leather to anyone, talk things out instead," he added, making the audience chuckle with his use of a popular colloquialism that means "don't speak ill of someone behind his back."
Francis in no time at all has achieved the status of a rock star in Argentina.
When he was archbishop of Buenos Aires the new pope had testy relations with President Cristina Kirchner, particularly over legislation on gay marriage, abortion and transsexual identity.
But on Monday, Kirchner met with Francis at the Vatican and asked him to mediate in the Falkland Islands' dispute with Britain.
Her late husband Nestor had called Bergoglio "the true head of the opposition" because of his behind-the-scenes meetings with political leaders.
Suddenly, political observers said, the ruling Peronist party and the opposition alike are tripping over each other to be seen as close to him.
"They all seem to be fighting, as if to say 'I saw him first, I see him more often,'" said sociologist Graciela Roemer.