FPTP in non-US contexts very regularly has >2 candidates, despite the risk of a spoiler. England has a 2.5 party system where the Lib Dems compete in every seat and win some. Scotland and Wales have nationalist parties in addition to this (and the Scottish National Party is currently overwhelmingly dominant in seats won, as a result of one of FPTP's other failure modes). Northern Ireland has a different party system with sectional voting and ~5 effective parties. Canada has the NDP and (in Quebec) the Bloc.

One of the classic results in political science is Duverger's Law, sometimes formulated as 'under first past the post the number of effective parties tends towards two', but 'tends towards' is doing an awful lot of work. One could unkindly suggest that, like a lot of political science results, it works better in the US than in the rest of the world. And I say that as a political scientist...

The 2000 US presidential election where Ralph Nader spoiled for Al Gore seems like a notable counterexample.