An easy way to go about this is to simply not have an easy task like that lying around. Instead, get things to where the real meat is. Turn things to eleven, as it where. If a single opponent would be no threat, lump them together into groups of 5 and suddenly they become a threat again. Sure, it's going to look much more spectacular as well, when you mow down 5 guys with one strike, but hey, that's what we're here for.
Look at the novels. In the beginning, Harry tells us about his tracking spell numerous times, how he draws the circle, how he needs this and that. In later novels, he basically does a dozen or so of them in one sentence. They simply aren't interesting anymore, so it gets skipped. That's pretty much what's happening in your example as well. If the outcome is all but certain, just go ahead and either take it for granted or throw a wrench into it to make it interesting again, upping the numbers into levels where failure is possible again.
You can also just go for a "you can't do this here" sort of compel. Force the player to go through a problem addressing his lower skills, before he can do something with his apex skills again. Because showing those off occasionally is simply a lot of fun.