I don't think that Fedor is a top ten heavyweight. I don't think he has been a top ten heavyweight since 2010. Fedor lost tonight because (a) he is older, with a lot of mileage on his body, and therefore slower; (b) not able to take a punch (or recover) as well as he was able to in his prime; and (c) Mitrione is a big man who hits hard.
Those aren't excuses at all. They compose an honest assessment of what happened tonight. An excuse would be something like, "well he lost because he slipped," or "Fedor only lost because it was an early stoppage." Fedor lost fair and square, and he didn't make excuse. You, however, are committed to disparaging one of the most respected sportsman in all of mixed martial arts.
I mean, cool, you're a real winner...