Boxing legend Marvelous Marvin Hagler has died at age 66.
Hagler, a former undisputed middleweight world champion, held a 62-3-2 record and won 52 fights by knockout. He ruled his division until a controversial split decision loss to Sugar Ray Leonard in 1987, which was his last fight.
"Today, unfortunately my beloved husband Marvelous Marvin passed away unexpectedly at his home here in New Hampshire," his wife Kay Hagler wrote on Facebook.
Hagler was known to be ill but a cause of death has not been confirmed.
"Marvelous Marvin Hagler was among the greatest athletes that Top Rank ever promoted," Top Rank chairman Bob Arum said.
"He was a man of honour and a man of his word, and he performed in the ring with unparalleled determination. He was a true athlete and a true man. I will miss him greatly."
Hagler defended his middlweight world titles 12 times. He is regarded as one of the greatest fighters of all time and perhaps the finest southpaw.
"I've gotten meaner since I've become champion," he told Sports Illustrated back in 1982. "They're all trying to take something from me that I've worked long and hard for, years for, and I like the feeling of being champ.
"There's a monster that comes out of me in the ring. I think it goes back to the days when I had nothing. It's hunger. I think that's what the monster is, and it's still there."
Hagler first won the WBA and WBC middleweight titles from Alan Minter via third-round TKO, at Wembley Arena in September 1980. He won the inaugural IBF crown with a fourth-round knockout of Wilford Scypion in May 1983, which he followed up later that year by beating Roberto Duran.
Hagler won the classic fight known as 'The War' against Thomas 'Hit Man' Hearns in April 1985, via a third round knockout. The first round of that fight is arguably the greatest in boxing history, a vicious and relentless slugfest. Hagler also knocked out John Mugabi before his fateful clash with Leonard.
"If they cut my bald head open, they will find one big boxing glove. That's all I am. I live it," Hagler once said of his career.
Hagler legally changed his name to add the 'Marvelous' moniker in 1982, annoyed that ring announcers weren't using his nickname. It became iconic and will never be forgotten by those who witnessed his career.