The first meeting between the pair of all-time greats took place in Montreal, the same city where Sugar Ray Leonard had won an Olympic gold medal in 1976.
The WBC welterweight title was on the line and so too were both boxers' reputations.
Leonard was 27-0 since joining the paid ranks and had become the WBC champion by beating Wilfred Benitez.
Duran, meanwhile, boasted a 71-1 record. His solitary defeat had come against Esteban DeJesus in 1972, but he still found himself the slight underdog going into the "Brawl in Montreal."
The bout was a classic. It was also difficult to score, as the two men gave it their all over 15 absorbing rounds.
In the end, the judges sided with Duran. After initially being given the nod by a majority verdict, it was later changed to unanimous decision after one judge's scorecard was checked again.
In the post-fight interview, Duran—per BoxRec—said: "He is the best I have fought. He hit me hard a couple of times, but I was never in bad shape. He was pretty good, but he had to be because he was fighting me."
The close nature of the bout demanded a rematch, and they duly did it all again later in the same year. The judges were not required the second time around, though, as Leonard won by TKO in the eighth round.
