If Gonzalez loses because he's not fighting smart anymore and is going toe-to-toe with Ippo which is eventually going to get him punched because that's Gonzalez's "true nature" or something, hahahaha!
Even if it was foreshadowed before the match, Gonzalez's true fighting nature, that is still one stupid way to make Gonzalez lose when he so clearly outmatched and could have won against Ippo by fighting smart. I believe that for most of his matches Ippo forced his opponents to go toe-to-toe with him when they were winning from long range. Gonzalez? He does it to himself. It would have worked better for me if Gonzalez wasn't getting anywhere with his long range careful fighting style so he decided to enter 'Metztli Mode' to make better progression. Nope, he just does it to start a street fight!
What happened to the smart world class boxer that thought 2 steps ahead and planned everything from the beginning of the match? Thrown out the window at the last second while you're winning!? I'm completely ok with Ippo winning, but this way? Eh…
Here's the interesting thing though. We heard from the mouth of "The Man" Martinez himself that Gonzalez's Metzli mode is stronger and harder to deal with than his by-the-book boxing style. So it wouldn't be too much of a stretch for him to bust it out when he thinks he's gained the upper hand. And as Sendo pointed out, rushing the dempsey roll is an effective method of containing and minimizing it's effect when you can't successfully counter it like Sawamura can. So he's kind of in an advantagous position if he can actually nail him here.
Besides, heroes winning due to faults of the villains or due to lucky breaks is nothing new. Rob Lucci could've just slit Luffy's throat rather than hurling the "rubber" man out of the window like a dumbass for instance.