Yes comfortably. In much the same way he took Barkley out at Middleweight, something Hearns couldn't do at either 160 or 175. Out of interest who do you think hit harder Hearns or McClellan?
I'd say "hard ****" Green and Curtis Parker were Mugabi's best along with Fletcher, flea...both decent fighters at the time.Maybe Hargrove too, as he was a vicious puncher, but he'd already been somewhat exposed as hype by Medal and never did anything after being mangled by the best. Mugabi definitely benefited from Duff's connections in getting that fight with Hagler though.Someone like Herol Graham or Kalule would have been more deserving circa 86.
Conversely I wonder why those same connections couldn't have made a fight with Jackson seeing as both were unbeaten bangers in the same division? I will say though, there is no way Jackson lasts anything like 11 rounds with Hagler circa 86. Marvin would just do what he did to Hearns and walk right through anything JJ throws and beat him up. Jackson lacked anything like the skills to bother Hagler, and would be there to be hit.
I watched the Hagler vs Mugabi fight a few days ago and it's one of those fights where you shake your head at the punches given and taken. Both were tremendous that night and Mugabi's power was frightening. Could Hearns take those same shots? I'm not so sure, although Hearns might not have to with his reach and speed advantages. Mugabi has a serious puncher's chance in my opinion. He was only great in one fight, but that one impressed me enough to give him hope against Hearns.
The same could be asked of Barkley and he managed to KO Hearns. I give the edge to Hearns based on his superior skills, accomplishments and his own power, but he'd have to fight the right fight. Against someone who could bang Tommy was always one punch from disaster.