Mancini was shorter but he was stronger, tougher and took a better punch, also likely a harder puncher. If Sean was battered by Andy Ganigan, it doesn't seem likely he could stand up to Mancini.
I have always picked Mancini whenever this question comes up. Ray was too well proven in wars against world class fighters. O'Grady had many fights, but was never really tested in battle to the extent that Mancini was.
Danny Lopez and Andy Gannigan both handed O'Grady his ass. Ray did not have that kind of punching power, but he probably had better "boxing skills." I think he would beat O'Grady down and get the TKO mid to late rounds.
Ray beat more established fighters at the lightweight class and didn't really duck anybody.Sean, for whatever reason, didn't try to fight Claude Noel and was beaten by Johnny Verderosa.Ray takes this fight by eighth round tko.
Ray Mancini always appeared to me to be at a true champion class level and O'Grady, whom I think some of you are underrating here, a notch below. I suspect O'Grady shows himself more durable and having more boxing skill than to get stopped abruptly, but either gets stopped on cuts while a few rounds behind on points and sliding down or loses a 6-7 point decision over 15 rounds.
I dont think Sean has a shot in hell. Mancini TKO 6. Just too strong, too heavy handed, and relentless for O'Grady to handle. Ray would beat O'Grady down just as he did Espana IMO.
I hate it when people say Mancini had "limited skills." Compared to whom? He is underrated as hell. Not an ATG, but he knew what he was doing in there. You don't lead Arguello after ten rounds or completely shut out Jose Luis Ramirez by having "limited skills." Doesn't work like that. O'Grady was a bit over-hyped though. Juuuust a bit. Mancini either stops him on cuts late, or decisions him by a fair margin.
It took a long time till O'Grady's chin lost is resistance..what people forget is that leading up to the Ganigan fight Sean was very tough and smart as a fighter...he even impressed Sugar Ray Robinson enough to say that "he fights like he's black"...O'Grady hets sold short here a lot and conversely Mancini gets overrated...think of the version of Boom Boom that got mauled by Bramble and at the end got decked and humbled by that great puncher GRAG HAUGEN...for fair? Fights that happened after Ray's chin and punch resistance was gone? That's exactly how you're judging O'Grady in regards to his Ganigan fight. O'Grady showed what his potential was vs Kenty...and that was at the tail end of what...70+ fights?
The Haugen fight is a terrible analogy considering Ray got TKO'd by Haugen was he was about 10 years past his prime. O'Grady got iced by Ganigan shortly after his career best performance against Kenty. Its not that he lost his punch resistance, he simply got destroyed by a big puncher. Mancini didnt hit as hard as Ganigan, but he hit hard enough to put O'Grady away eventually. Its just a bad matchup for Sean. He wouldnt be able to outbox Mancini, and Ray would force him into a brawl in which Mancini being the stronger, more powerful, and more durable of the two would be the deciding factor. Actually its more then just styles... Mancini was just plain and simple a better fighter then O'Grady. A better matchup for Sean would be him vs Haugen. I give O'Grady a better chance there.
I would take the Ganigan that Ko'd sean on Halloween 1981 or fought Alexis in May, '82 to ko Boom Boom anyday.