decisive battle; deciding match; play-off
明日がいよいよ決戦だ。
Tomorrow is finally the decisive match.
チームの決戦は来週に迫っている。
The team's decisive match is drawing near next week.
歴史に残る決戦が繰り広げられたのが関ヶ原だ。
Sekigahara is where the historically defining battle was fought.