鎧袖一触

Etymology
From 🇰🇲. Attributed to Minamoto no Tametomo, according to the Nihon Gaishi by Rai San'yō:
 * "ja"

- 至如平清盛輩、臣鎧袖一触、皆自倒耳

Idiom

 * 1) to defeat an opponent in a single blow