fluke; lucky break; chance occurrence
Refers to an unexpected stroke of luck, often in sports or games like billiards. Carries a nuance of something happening by chance rather than skill.
あのゴールは完全にフロックだった。
That goal was a complete fluke.
ビリヤードでフロックが入って勝った。
I won because a lucky shot went in during billiards.
He won the championship by a fluke.
I think that home run was just a fluke.