The Civ 5 Cultural Victory

My Civ 5 playing has mostly revolved around the Cultural Victory. It's a rather fragile way of playing, since there are a couple of computer-controlled civ playstyles that can ruin it. If you start between Japan, Greece, and Persia, it's going to be really, really hard, because even if you kick all their buts, if you devote much production to military units, the cultural victory slips away. You have to build certain improvements, and specific wonders(Oracle, Sistine Chapel, Cristo Redendor, Sydney Opera House) by a certain time or you are screwed. In particular, Sistine Chapel and Cristo Redendor are game-breakers. If another civ builds one, you need to drop the cultural victory right then and there. I got to where I could win a Cultural Victory nearly any time with any civ at Warlord, so I moved up to Prince. I got to where I could win a Cultural Victory with any civ some of the time, and culture-favored civs(Egypt, France, Siam, India) most of the time, so I moved up to King. Now I am having some big problems. I came within 2 turns of success with France. Then I had an ideal scenario playing as Egypt where I had a large island all to myself. However Persia was so ridiculously far ahead in tech and had about 20 cities, then produced Cristo Redendor about 5 turns before me (game over). I have no doubt that a cultural victory is possible even on Emperor level, since higher difficulty means making things easier for other civs, not penalizing yours. So as long as you stay out of war and somebody like the above example with Persia does not happen, you should be able to do it. I just have not done it yet. Today I try again as France. But one thing I am not sure about is whether I will ever be able to get a Cultural victory with a culture-unfriendly civ at King or higher. I almost did with China, hell I guess that is possible too for the same reasons, just gotta keep trying.