真剣勝負

Meanings

1. Noun

   fighting with real swordsFour-character idiom
2. game played in real earnestFour-character idiom

• おやおや。いかな体育たいいくの授業じゅぎょうといえど・・・真剣勝負しんけんしょうぶの意気込いきごみで臨のぞまなければ、いざ実戦じっせんと言いう時ときに役やくに立たちませんよ。

  Well, even if it is just P.E. class, if you don't take it seriously, it won't do you any good in a real match.