happy chance(n = noun.event) break, good luck - an unexpected piece of good luck; "he finally got his big break"
is a kind of accident, chance event, fortuity, stroke

by chance, chance, chance event, chance on, chance upon, chance variable, even chance, fair chance, fat chance, game of chance, good chance, happy, happy event, happy hour, happy medium, make happy, no chance, off chance, outside chance, slim chance, small chance, sporting chance, take a chance, trigger happy