An Argentine judge paved the way for gay marriage when she granted a homosexual couple permission to marry in a first for Latin America, the world's biggest Catholic region.
Buenos Aires, known for its active if low-key gay movement, became the region's first city to approve civil unions for gay couples in 2002. It was followed by Villa Carlos Paz in the north and the southern province of Rio Negro.
Those civil unions grant gay couples some, but not all, the rights enjoyed by heterosexual married couples.
Friday's ruling by Judge Gabriela Seijas ordered the civil registry to make official the marriage of Alejandro Freyre, 39, and Jose Maria Di Bello, 41, who had been denied their request because they were both men.
It could increase pressure for lawmakers to take up a stalled gay marriage bill in Congress.
"We are very happy, moved, but we also feel the heavy weight of responsibility because it's not just about us, it's encouraging legal equality in Argentina and the rest of Latin America," Di Bello told AFP.
The couple had filed a complaint in April.
In the rest of Latin America, Mexico City, the Mexican state of Coahuila and the Brazilian state of Rio Grande do Sul, also allow civil unions for same-sex couples.
Uruguay became the first country in the region in late 2007, to legalize civil unions for gays. In January 2009, the Colombian Constitutional Court recognized a series of rights for homosexual couples, including social welfare rights.
But no Latin American country authorizes marriage between gays.
Seijas deemed that "the law must treat everyone with the same respect according to their particular situation" and declared unconstitutional two articles of the civil code, including one stating that marriage is only between a man and a woman.
"All you have to do is change the words 'man' and 'woman' with the word 'party,'" said Di Bello, who along with his partner is HIV-positive.
The Catholic church is especially powerful in Argentina, a country whose population is 91 percent Catholic.
Bishop Baldemoro Martini charged that "same-sex unions do not contribute to the public good; they put it especially at risk."
The landmark decision could still be struck down if there is an appeal.
But Buenos Aires Mayor Mauricio Macri, a conservative, said the government would make no such move.
"The world is heading in this direction," he told reporters.
Several homosexual groups hailed the judge's ruling.
"I am very happy and I join the feeling of Argentine gays, who were repressed for many years," said Marcelo Cerqueira, president of Gay de Bahia, one of the most active gay rights groups in Latin American giant Brazil.
"For us in Brazil, we have no expectations, neither in court, nor in the medium or long term."
The decision by Seijas "is incredibly courageous, we didn't expect it," acknowledged Di Bello, who fell into his partner's arms when he learned of the verdict.