Argentine boxer Hugo Santillan died on Thursday from injuries suffered in a fight on Saturday, the second such death in just two days after that of Russian Maxim Dadashev in the United States.
Santillan, who was 23, collapsed while the result was announced of his 10-round draw with Uruguayan Eduardo Abreu in San Nicolas, just north of the Argentine capital Buenos Aires.
He was taken to hospital where he underwent an operation to relieve pressure due to swelling on the brain caused by a head trauma, hospital sources said. He died of a heart attack.
Dadashev died on Tuesday from brain injuries suffered in his fight with Puerto Rican Subriel Matias on Friday night in Maryland. He was 28.
Nothing appeared wrong with Santillan as he fought to a draw with Abreu but while waiting to hear the result announced, he collapsed and lost consciousness.
He was fighting for the World Boxing Council (WBC) Latino Silver lightweight title, held by Abreu.
"We join Hugo's family and friends in grief," said the WBC on Twitter.
Santillan's previous fight, a 10-round points defeat to Artem Harutyunyan in Germany, was only five weeks earlier.
Santillan had a record of 19 victories, eight by knock-out, six defeats, two by stoppage, and two draws.
A professional since 2015, he won the South American super featherweight title in September 2016 but lost it four months later in his first defense.