I just beat Krezio who is rank 15 of limited league as a rank ~200ish of rare league and only went up 90 rankings? That should be a huge boost to rank! Seems very minuscule.
Once again, rank =/= experience. Just because you beat a limited league ONE time doesn't mean you're going to end up in limited league. With all the players around your ranking it's easy for them to be gaining more experience than you are, thus you only going up 90 ranks.