I feel like Holmes overall talent and ability will prevail but not before he visits the canvas one time. Jimmy Ellis, this is not the guy you want to lose your concentration against. Holmes had a tendency to drop that jab on the way back. A fighter like Ellis would be looking for that and he had the type of sneak right to make Larry pay. Holmes would get up and gut it out. Holmes TKO 11.
This a very tough fight for Larry because he's in with a guy who fights much like him. Ellis is not a pure boxer or a pure puncher, but a mix of both. Ellis is a faster starter than Larry and could give Holmes trouble early. Ellis had killer instincts which would be dangerous for a hurt Larry. But Larry was incredible durable, and like ETM said, Ellis had the precision and power to probably land a perfect right overhand like Shavers did and drop Holmes. Ellis had a tendency to expend too much energy early on, and I see Holmes stopping a tired Ellis on his feet in the double digits after the vicious brawl that ensues upon Holmes being floored. In all actuality, this fight would be similar to Holmes' fight with Shavers, except Ellis would be much more competitive before the knockdown than Shavers was.