快刀斷亂麻 [－－断乱－]

Jyutping faai3 dou1 tyun5 lyun6 maa4
Pinyin kuài dāo duàn luàn má

Definitions (CC-CEDICT)
  1. lit. quick sword cuts through tangled hemp (idiom); decisive action in a complex situation
  2. cutting the Gordian knot