With Ultron in that badass mofo look, there's no way he could lose. Lol.
Seriously, Apocalypse may seem to have the upper hand with some of his more ludicrous abilities. But ultron recently has gained a Colossal boost in power lately a lot more than most characters have gotten So that can minimize that detail. Plus ultron is made out of the nearly indestructible material Admantium. Attempting to damage him in any physical way shape or form has proven to be nigh impossible by even the likes of Thor and Sentry. And A Chaos magic Boosted ultron made mincemeat out of Thor, and the rest of the avengers for that matter.