'A' level vs 'B-' level. Easy to pick. Chavez wins every round and stops iron-hearted Gatti in 7-8 rounds.
It would be an exciting fight where Gatti would receive a brutal career shortening, maybe even career ending beating.
Chavez by brutal mid rounds stoppage. If Gatti stands toe to toe he'll get stopped faster If he tries to move and box, he will last longer, but Chavez will pressure him early, go the body, slow his movement, then grind him down.
This fight would be similar to the final 6 rounds of Chavez V Rosario. A beat down of the highest order. Gatti trades too often and was inconsistent with his boxing. He would start a round jabbing and moving yet by the end he is mixing it up gritting his teeth. Defensively Gatti was sub par and whilst under McGirt he showed flashes of some head movement he was never difficult to tag. Chavez backs him up easily and scores heavy with the body shots. Mickey Ward had great success in the first Gatti bout with the left rip. Chavez would have exactly that plus more. When stunned Gatti often tried to place his head below an opponents chin inside for a rest, however he does this without clinching and had his arms by his side. Ward teeded off on him every time Gatti did that in their 3 bouts. Chavez would mince him on the inside if Gatti tried that.
Such a mismatch the result would be criminal, Chavez would put a historic beat down on Gatti. His bad defense insures he's easy to hit, his chin, toughness, and heart ensure he's there to bow beaten on for an extended period of time.
I love Arturo but Julio kicks his ass. No way of getting around it. Gatti would show a ton of heart and wouldn't go out quietly but this is a no win situation for him barring some crazy fluke.