I was doing
some reading on this topic just now and discovered that, apparently, Uruguay did not actually illegalize pistol dueling until
1992, with multiple gun duels between liberal and leftist politicians having occurred in the early 1970s (though none of the duelists were ever killed as far as I've read). The last duel I was able to find that happened in the country was approved by the government and conducted on October 17, 1971, when, according to
this newspaper from Pennsylvania and a separate
British paper from Birmingham (two of the best English-speaking reports of the event that I found), the Uruguayan Interior Minister Danilo Sena was insulted by the country's former Minister of Industry, a fellow named Enrique Erro.
Erro had called Sena a coward, and so Sena challenged him to a duel, to which a court then approved the clash as permissible under Uruguayan law. Days later, the two would meet in a field behind a military school carrying handguns (I'm assuming these firearms were revolvers) loaded with two rounds. After preparing their weapons and setting a distance, they both fired their guns at one another, and all four of the shots were missed.