Tā shì wǒ de shǒuxià bàijiàng, gēnběn bùshì wǒ de duìshǒu.
He is a general I have already beaten - no match for me at all.
Tips
usage
败将 often appears in the set phrase 手下败将 (someone who has been defeated by you). It can be used figuratively in sports, business, or any competitive context.