fluke 侥幸;偶然;意外 by a fluke 侥幸

【例句】
She won the writing contest by a fluke. She had only spent 20 minutes writing her essay.
她侥幸赢了作文比赛，她写那篇文章才花了二十分钟。

You dolt! You can't beat me! Not even by a fluke of fate!
你傻啊！你根本无法打败我！即使你有侥幸的运气。