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.
In the bottom of the ninth, his one swing turned the game around and the team won.
逆転 is a general reversal or turnaround, while 一打逆転 specifies a reversal caused by a single hit or swing, often in sports.
Compound of 一打 (one hit/stroke) and 逆転 (reversal). The exact origin is uncertain, but it likely emerged in sports commentary to describe a dramatic game-changing play.