The best i could think of was "windfall" meaning an event that brings a sudden stroke of luck, equally unexpectedly.
J.R.R. Tolkien made up a word to fit that exact definition which he called "eucatastrophy", adding the latin prefix "eu", meaning good. He used it to define the epic, sudden and happy resolutions of hopeless situations in his stories.
a huge catastrophe
No, catastrophe is a noun.
The Apocalypse (revelation) is the last book in the Bible, and therefore its antonym is Genesis, which is the first book. The word apocalypse means "un-hidden, hence revealed," for which the antonym is mystery, which means " kept secret, not spoken." It depends on which type of apocalypse you are talking about, but if it is the one meaning "catastrophe," then some antonyms for it would be "benefit, blessing, favor, miracle, wonder, success."
'Catastrophe' has four syllables.
The earthquake in China was a major catastrophe.
Hijacking Catastrophe was created in 2004.
Catastrophe - book - was created in 2009.
Family Catastrophe was created in 1972.
Causing a Catastrophe was created in 2002.
Nedelin catastrophe happened in 1960.
The Ultraviolet Catastrophe was created in 1998.
U-Catastrophe was created in 2007.