Oscar. DLH got a REAL knockdown in the first on Gatti. DLH is a better puncher. Floyd's KD was a cheap shot. But to be far Floyd was bearly hit, and Oscar took some shots.
Floyd for sure. Started things off with a cheap shot sucker punch which would've done a tonne of damage before the beating intensified, and the final rounds were brutal. As has been said, Oscar just overwhelmed him with his strength and size which counts for less in my book. Gatti also landed some thumping punches as Oscar chose to slug not really taking Gatti very seriously as he knew it was a complete mismatch
They both completely destroyed Gatti but I agree with your thoughts on Floyds showing all of his abilities in that fight. That is one of my all time favorite fights even though it was so one sided Floyd got busy. That was high level stuff against a very strong, durable champion. Stylistically Gatti was tailor made for Floyd but that was still a masterful performance which exceeded all expectations.