Both could bang. The aggressive southpaw Johnson against the right-hand wonder Lalonde, who was a bit handicapped with what he could do with the left but seemed to (at the very least) stun anyone he hit with that right hand. Let’s make it 12 rounds in Las Vegas for a neutral venue, but I don’t see it going the distance. Who lands first? Or just who lands best and last? Who ya got?
Johnson would have to be wary of Lalonde's huge right hand, but short of that he beats up and stops Donny.
I have to go with Johnson, Barring something big coming from Lalonde out of nowhere ( which could happen. ) neither of these guys were poster boys for durability but both could bang. Marvin was more proven at world level.
I could see either winning and I’m going to say both go down in the first five rounds before Pops’ body attack starts to wear down Lalonde and Marvin gets the stoppage in seven or eight.
Lalonde could punch with the big right and if he lands cleanly with it, Johnson will know about it. Marvin is the better fighter overall imo, more proven at higher level and it's likely he'd outbrawl Donnie and win by stoppage, maybe mid rounds.
I could see Johnson dominating Lalonde then getting hit with that righthand and end up getting finished. For Lalondes short comings he could hit with that righthand.
Sugar Ray Leonard, a natural welterweight- albeit one of the greatest welters and pugilists of all time- kod LaLonde at 168. Pops decapitates him
It took a twelve round war with Saad Muhammad for it to be cracked. His chin was only bad when he was tired.