He competed in boxing from 1973 to 1987 and reigned as the undisputed champion of the middleweight division from 1980 to 1987,[3] making twelve successful title defenses, all but one by knockout.Hagler first put on gloves at the age of ten, for a social worker he knew only as Mister Joe, who taught him sports and got him involved in counseling other children.Ida Mae recalled her eldest son had always wanted to box and promised one day to buy her a home.[18] Following the riots of 1967 in which 26 people were killed and $11 million in property damage was caused, including the destruction of the Haglers' tenement, his family moved to Brockton, Massachusetts.He first entered Vinnie Vecchione's gym (where, unknown to him, Dornell Wigfall trained), but after one week watching, and of nobody speaking to him, Hagler decided to leave for good.In May 1973, Hagler won the National Amateur Athletic Union (AAU) 165-pound (75 kg) title after defeating Terry Dobbs, a U.S. Marine from Atlanta, Georgia.In November 1979, Hagler fought world middleweight champion Vito Antuofermo at Caesars Palace in Las Vegas, Nevada.With Hagler dominating the action, referee Carlos Berrocal halted the fight during the third round to have the four glaring cuts on Minter's face examined.Hagler and his trainers had to be escorted to their locker room by a phalanx of policemen, all the while enduring a steady rain of beer bottles and glasses.British champion (and mutual Alan Minter conqueror) Tony Sibson followed on Hagler's ever-growing list of unsuccessful challengers.Sibson provided one of the most entertaining (to this point) fights of Marvelous Marvin's career, but he ultimately fell short, lasting six rounds.Then came Juan Roldán of Argentina, who became the only man to be credited with a knockdown of Hagler, scoring one mere seconds into the fight.Round Three: The pace slowed until referee Richard Steele called a time out to have the ringside doctor examine the cut on Hagler's head.Next was Olympic silver medalist John Mugabi of Uganda, who was 26–0 with 26 knockouts and was ranked the number one contender by all three major bodies.Many ringside observers, including analyst Gil Clancy, noticed that Hagler was showing signs of advanced ring wear and age.He had also completely morphed his ring style from a slick, quick-fisted, boxer/puncher to a strictly flat-footed, stalking, slugger to compensate for his loss of speed and reflexes.Hagler's next challenger was Sugar Ray Leonard, who was returning to the ring after a three-year retirement (having fought just once in the previous five years).As Leonard tired he began to clinch with more frequency (in total referee Richard Steele gave him over 30 warnings for holding, although never deducted a point).Hagler began dancing in celebration of his performance while Leonard collapsed to the canvas and raised both his arms in triumph.Leonard was announced as the winner and new middleweight champion of the world by split decision (118–110, 115–113, 113–115), a result which remains hotly disputed to this day.[33] Duane Ford, chairman of the Nevada State Athletic Commission, commented that Guerra probably would not be invited back to Las Vegas to judge a fight in the near future.[35]Hugh McIlvanney, commenting in the British Sunday Times and Sports Illustrated: What Ray Leonard pulled off in his split decision over Hagler was an epic illusion.His plan was to "steal" rounds with a few flashy and carefully timed flurries and to make the rest of each three-minute session as unproductive as possible for Hagler by circling briskly away from the latter's persistent pursuit.When he made his sporadic attacking flourishes, he was happy to exaggerate hand speed at the expense of power, and neither he nor two of the scorers seemed bothered by the fact that many of the punches landed on the champion's gloves and arms.[36][37]McIlvanney also referred to Budd Schulberg's contention about a 'compound optical illusion', namely that by being the underdog and more competitive than expected against the dominant undisputed champion in Hagler meant that Leonard appeared more effective and to be doing more than he actually was.Jim Murray, long-time sports columnist for the Los Angeles Times felt that Leonard deservedly got the decision, arguing that Leonard showed better defense and ring generalship, landed more punches and writing: It wasn't even close...He didn't just outpoint Hagler, he exposed him.[39][40] Fourteen months following their fight, Hagler retired from boxing on June 13, 1988, after watching WBA middleweight champion Sumbu Kalambay prevail over his brother, Robbie Sims, via unanimous decision.Just a month succeeding Hagler's retirement, Leonard announced another boxing comeback to fight against WBC light heavyweight champion Donny Lalonde at the 168-pound (76 kg) super middleweight limit.Another foray by Hagler into the entertainment field included work on the video game Fight Night: Round 3.[46] On March 13, 2021, Hagler's wife, Kay, announced that he had died of natural causes at his home in New Hampshire at the age of 66.