真剣勝負

Meaning

1. n
   fighting with real swords
2. n
   game played in real earnest

Example sentences

• おやおや。いかな体育の授業といえど・・・真剣勝負の意気込みで臨まなければ、いざ実戦と言う時に役に立ちませんよ。

  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.