Mexican boxer Francisco Leal has died of a brain injury in a San Diego hospital, four days after collapsing in the ring following a fight with Raul Hirales.
The 26-year-old super-bantamweight, nicknamed 'Frankie', was taking part in a televised bout in Cabo San Lucas where he was twice floored by his opponent.
Leal was first sent to the canvas in round six, before Hirales sent him crashing down for a second time in the eighth.
He survived the referee's count before he collapsed and was carried out of the ring.
He was taken to hospital and, after slipping into a coma, was transferred to San Diego.
Promoter Fernando Beltan told ESPN: "Frankie was a good kid, a great fighter, a warrior in and out of the ring.
"As a company we took responsibility and tried to save his life as much as humanly possible.
"Now we are united in the grief felt by his family and his boxing family. We will try to help, whatever is needed."