相撲すもうに勝かって勝しょう負ぶに負まける

expression, ichidan verb

win the battle but lose the war; fail at the last moment despite an advantage

Idiomatic expression originating from sumo: you may dominate in technique (win the sumo) but still lose the match (lose the contest). Used broadly for situations where tactical success does not lead to overall victory, or when a favorable position is squandered at the end.

• 交こう渉しょうでは細こまかい条じょう件けんで勝かっても、最さい終しゅう的てきに契けい約やくを逃のがせば相撲すもうに勝かって勝しょう負ぶに負まけることになる。

  In negotiations, even if you win on small points, if you lose the contract in the end, it's a case of winning the battle but losing the war.

• 彼かれは議ぎ論ろんでは優ゆう勢せいだったが、結けつ論ろんでミスをして相撲すもうに勝かって勝しょう負ぶに負まけた。

  He had the upper hand in the debate, but made a mistake in the conclusion and ended up winning the battle but losing the war.