Former three-time middleweight world title challenger Juan Domingo Roldan, the powerful and rugged Argentinean, died from Covid-19 on Wednesday in his hometown of San Francisco, Argentina. He was 63.

The barrel-chested Roldan grew up on a dairy farm and eventually emerged as one of Argentina’s best fighters during the 1980s, but he is best known for the losses he suffered in world title fights against Marvelous Marvin Hagler, Thomas Hearns and Michael Nunn.

“He was a gutty warrior and he fought all the top guys,” said Top Rank chairman Bob Arum, who promoted all of the fights Roldan had in the United States and got to know him. “He was a wonderful, wonderful fighter, a real professional, a totally nice guy. The people with him were lovely people. His promoter, (the late International Boxing Hall of Famer Tito Lectoure), was a dear friend of mine.

“As a person, I couldn’t rave enough about him. As a fighter, he was a determined warrior. He always came in prepared. He was a true professional. Usually when somebody dies you say nice things about him but if you’d have asked me a month ago before he got hit by Covid I would be saying the same things.”

Roldan (67-5-2, 47 KOs), who fought many of his bouts in the same city as his death, boxed from 1978 to 1988, primarily in his home country. But of the nine fights he had outside of Argentina, seven, including the ones he is most famous for, took place in the U.S.

Roldan lost two fights at home to Juan Carlos Bogado and Ricardo Arce but had avenged both defeats before arriving in the U.S. to put himself in position to challenge Hagler for the undisputed 160-pound crown.

During a five-fight stretch in 1983, he fought three times in the U.S. on Hagler undercards as he was being groomed for a world title shot. In February of that year, Roldan knocked out Wilbur Henderson in the seventh round under Hagler’s title defense against Tony Sibson. In May, Roldan won a 10-round decision over Teddy Mann on the night Hagler knocked out Wilford Scypion. And in November, Roldan scored a sensational sixth-round knockout of Frank “The Animal” Fletcher, depositing him face first on the canvas courtesy of a ferocious right hand on the undercard of Hagler’s 15-round decision over Roberto Duran.

Arum recalled Roldan’s devastating punch. “The referee came over to Fletcher and said, ‘Do you know where you are?’ And Fletcher says, ‘Sure, I’m in Atlantic City.’” The fight, of course, took place at Caesars Palace in Las Vegas.

Roldan’s knockout of Fletcher set the stage for him to challenge Hagler for the undisputed title in his next fight in March 1984 at the Riviera Hotel & Casino in Las Vegas.

Although Roldan got stopped in the 10th-round of a game effort – he fought most of the bout with a swollen right eye after being accidentally thumbed -- he scored the only official knockdown against Hagler in his 14-year, 67-bout career, albeit a debatable one on a left hook/semi-rabbit punch, in the first round of the fight.

Following the loss, Roldan reeled off 11 wins in a row before returning to Las Vegas to knock out contender James Kinchen in the ninth round on the April 1987 undercard of the famed middleweight championship showdown between Hagler and Sugar Ray Leonard.

Two fights later, in October 1987 at the Las Vegas Hilton, Roldan challenged Hearns for the vacant WBC middleweight title that Leonard had vacated after defeating Hagler. Although Hearns knocked Roldan out in the fourth round, Roldan gave Hearns a very tough night and nearly stopped him earlier in the fourth round.

“I remember that,” Arum said. “He had Hearns out and then Hearns cold cocked him.”

Hearn’s win over Roldan made him a footnote in boxing history as the man against whom Hearns had become the first fighter in history to win world titles in four weight divisions.

After returning to Argentina and winning two fights in a row, Roldan came back to the Las Vegas Hilton in November 1988 to challenge Nunn for his IBF middleweight title. Nunn knocked Roldan out in the eighth round of what turned out to be Roldan’s final fight. Roldan would retire to life in Argentina, where he owned a ranch.

Dan Rafael was ESPN.com's senior boxing writer for fifteen years, and covered the sport for five years at USA Today. He was the 2013 BWAA Nat Fleischer Award winner for excellence in boxing journalism.