Stupid diplomatic victory ...

Again, my attempt to get a domination victory has been foiled by the evil diplomatic victory.
How many times have you gotten an unexpected diplomatic victory?

EDIT: I just realised that this wasn't clear at all; I won the diplomatic victory. A different Civ built the palace, and everyone had the same religion in all their cities. For some reason, everyone voted for me ... (I was at war with one of them, and the rest of them were worst enemies with my Vassal)

I remember a 30 hour game I lost when I accidentally voted for the AI and they won by 1 vote.

These days I tend to burn down the Apostolic Palace city if I don't control it.
Same with the UN.

Just have to start the war the turn of the latest vote so you get 10 turns of uninterrupted war.

I only lost towards the AP once, don't know how many hours I had spent on the game I think something between 5 and 10 and there was nothing that I could do afaik. I think I was so stupid to take Hatty into my round and the other AIs were Mansa and again an AI witout Mysticism and then Hatty founded a religion, that religion got dominant, she bulbed Theology like she always loves to and therefore had the AP safe and with everybody liking here there was nothing that I could do.

In most of my games I pay heavy attention towards the AP. The vote for religious victory i. e. needs all civs to have at least 1 city of the AP-religion, so I'd rather let a civ live with 1 city that doesn't has the religion if spreading the AP-religion so widely in ones own cities is not viable.

If the vote is possible I try to change the diplomacy in that way that the candidate doesn't has too many friends so I i. e. bribe him out of the favourite civic of other civs or I make civs change their religion etc.
Sometimes I've spread the AP-religion mostly because of wanting to have enough safety in the votes but I ofc. try to prevent that because spreading 1 religion is already expensive, spreading 2 is imo. really not reasonable.

I guess it's an advantage of playing on larger maps with more AIs that I don't think I've ever even seen the AP diplo victory vote. Never happens that every civ gets the AP religion. The most annoying thing the AP does is stop my wars sometimes.