Definitely Zarate. He either gets Canizales out of there late, or he wins a clear UD. I don't think Canizales would get past Zarate's height, and range. Orlando did NOT have the boxing ability, strength, and explosiveness that Gomez had.
Canizales was a very good boxer, underrated I think, but no way he has a shot, Zarate 9 out of 10 x, anyone could get lucky once, but that's it.
I would point to Zarate in this one and without hesitation. Although Canizales had a beautiful style, to me he represents a guy who was prolific in an era with multiple world title belts. He accumulated a series of defenses but never had those capstone performances to stand above the routine mandatory defenses. Imagine if Winky Wright never got his wins over Mosley and Trinidad for example and you have a picture of what Canizales' situation is history. By comparison Zarate is a true titan of the sport and is a no-brainer pick for a Bantamweight Mt. Rushmore.
Zarate KOs him, but not easily as some think. H2H Canizales is better than Davila (though Davila fought better competition) and Davila gave Zarate trouble. Would be a firefight while it lasted.
I've watched several fights with both of these guys lately, and the more I saw of Orlando the more impressed I was, even though i saw him in my youth, I had forgotten alot, the more I watched of Zarate, the more I was not impressed, yes a good solid all around fighter, good defense, very technical and well coached fighter, but his power did not seem to show up as he stepped up in quality of his competition, he fought and KOed a ton of bums, so I'm doubting his power was as great as many have rated him at. He could give anyone a tough solid match, but I'm not sure he is as great as rated everywhere i look on the net, he probably can pull this one out, but I'm rooting for Canizales, i wish they could have fought would have answered a lot more Zarate questions.