切中要害

qièzhòngyàohài
  1. to hit the target and do real damage (idiom)
  2. fig. to hit where it hurts
  3. fig. to hit home
  4. an argument that hits the nail on the head

CEDICT

Entry Composition

1 切中 qièzhòng to hit the target (esp. in argument); to strike home
2 要害 yàohài
  1. vital part
  2. (fig.) key point
  3. crucial