There is a way to cheat, and cut things down to two operations, but you have to manually edit the url. If I took the original url from the recent comments and edited the "context" parameter to something ridiculously large, like this, then the context is large enough that it will show me the top level comment, and all I have to do is hit permalink.

Actually, the "context" option only goes up to 8; numbers higher than that still only show 8 extra comments. I usually don't hit permalink, since I'm usually only immediately interested in the thread leading directly to the post I'm looking at, but in threads more than 8 comments deep it'd be nice to be able to skip to the top immediately rather than having to add context=8, click permalink, add context=8 to the new URL, click permalink again, and so on an unpredictable-in-advance number of times to finally reach the top of the thread.