一いち打だ逆ぎゃく転てん

noun

complete turnabout with a single hit; dramatic reversal from one swing

Primarily used in baseball or similar sports to describe a situation where a single hit completely reverses the game's momentum or score. Can be extended metaphorically to other dramatic one-shot reversals.

• 九きゅう回かい裏うら、彼かれの一いち打だ逆ぎゃく転てんでチームが勝しょう利りした。

  In the bottom of the ninth, his one swing turned the game around and the team won.