Duran won 63/ 64 of his fights at lightweight. He won 53 by knockout. That's an 84% knockout-to-win-ratio. Brown had 56 knockouts in 125 wins at lightweight. Brown was not as big of a puncher, but many of his wins came by early knockouts. He was also very dangerous late in a fight. Both Duran and Brown faced the top lightweights of their eras. My tendency is to go with Brown, but I think this fight would be pretty close.
I actually like Brown for the upset as well. He has the tools to give Duran a rough night, great movement and jab, strong counterpunching, good defense. I think Brown could measure and time Duran over 15 rounds to nick a close decision. Duran isn't an easy fight for any lightweight of course, but Brown has the speed, two fisted power, and boxing ability to pull it off.
I actually forgot about Armstrong. Yes, add him to the fold of a lightweights with a legit chance. Not Arguello. Love Alexis, he was an amazing fighter, but Duran was just better. And bigger. Ortiz would have a better chance than Arguello.
I’d say Carlos Ortiz at his best would be able to compete with Duran as well. For me it’s Whitaker, Williams, Armstrong, Ortiz that have the best shot against Duran. I’ll add Benny Leonard to the mix too. Ray Arcel even said that Leonard was the best fighter he’s trained.
As for this fight I think a focused Joe Brown can beat Duran 1/3 fights. An on point Joe Brown was a brilliant boxer at times.
Ortiz would have a chance because he was extremely physically strong at 135 and Duran wouldn't be able to just manhandle him the way he did most guys. Ortiz was also a superb infighter. Ultimately, I wouldn't pick Ortiz. I think Duran would be a bit too quick and dynamic for Carlos, and would win a clear decision. But Ortiz would certainly give him a tough night's work.
I’d put my mortgage on Duran winning. No disrespect to Old Bones but Duran was flat out better by a distance stylistic intangibles or not. Brown had a good run for a bit but was eminently beatable pre and post title. Duran was an animal at 135 who overcame an array of types and styles. Duran late stoppage or wide UD.
Brown beating Duran !!!!! C,mon guys, have you forgotten the ferocious, wasp waisted, lean mean fighting machine that the Duran was, total, I mean TOTAL self belief, almost a maniacal approach to his work, loved inflicting pain and hurt on his so called challenges, remember the reply when asked if he had been in better shape would he have stopped Lampkin earlier, came the reply " if I had been in better shape, he would have gone to morgue, not the hospital " this Duran was in my eyes could not have beaten by any Lightweight in history bar none.