Sisnorio, a former WBC youth champion, underwent emergency surgery on Friday to remove a blood clot from his brain after he fell unconscious on his way to dinner several hours after recovering from his fourth-round knockout, according to Superbox.com.
The 24-year-old failed to regain consciousness after surgery and died of heart failure at 9.15 p.m. on Saturday, an official at Bangkok’s Piyamin hospital was quoted as saying.
Sisnorio went down in the fourth round after suffering a barrage of right hooks in Friday’s super-flyweight bout with 37-year-old Chatchai (59-3), who has won his last six fights, four by knockout.
The Filipino fighter lost his last three fights and was defeated by TKO two months earlier in a tune-up bout with record-breaking Thai flyweight Pongsaklek Wongjongkam.
Sisnorio won just five of his 11 fights since turning pro in 2003.
Bangkok-based journalist Scott Mallon, in a report to Philboxing.com, said he’s "deeply saddened by Sisnorio’s death."
"He was a tough little guy who always fought hard – and he was so young. All my past words scolding the Thais for their ridiculous mismatches have now reared their ugly head," said Mallon in an email.
Insiders have informed that Sisnorio was flown out of the country without passing through the Games and Amusements Board (GAB), the agency tasked to regulate pro boxing in the country.
"I don’t know whether or not Sisnorio stayed in Thailand after he lost to Wonjongkam but since when is GAB clearance ever needed by a Thai promoter? I know the promoters could care less whether or not he had clearance. Some major reform is needed in Thailand but I wouldn’t count on it happening," added Mallon, who has been at the forefront of calls for boxing reforms in Thailand, especially concerning mismatches.
The GAB has been having problems controlling unscrupulous matchmakers who are virtually practicing human trafficking for fights abroad.