From Longman Dictionary of Contemporary Englishtrust to something phrasal verbHOPEto hope that what you want to happen will happen, because there is nothing you can do about it I’ll just have to trust to luck that it works out okay. I hope I may trust to your discretion. → trust→ See Verb table
Examples from the Corpus
trust to luck• If you don't want a child - don't trust to luck.• The men disappeared behind a distant quayside shed, but she dared not trust to luck and hid behind a winch.• I swayed and stumbled along as best I could, trusting to luck and the two people with me.• And trust to luck that whichever of the gods claimed him as of right would be in a forgiving mood. 