長驅直入

长驱直入
chángqūzhírù
  1. to march straight in unchallenged (military) (idiom)
  2. (fig.) to push deep into the heart of sth
  3. to flood in

CEDICT

to rapidly push straight into a place with irresistible force

Wiktionary

挺進迅速，銳不可擋。《水滸傳．第一○七回》：「自此盧俊義等無南顧之憂，兵馬長驅直入。」《蕩寇志．第二一回》：「那廝若得了清真山，長驅直入，為患不小。」也作「長驅徑入」、「長驅而入」。

重編國語辭典

挺進迅速，銳不可當

維基詞典

Entry Composition

1 長驅 chángqū
  1. (formal) to advance rapidly over a long distance
  2. to advance rapidly over a long distance
2 直入 zhírù
  1. (literary) to go straight into; to walk straight into
  2. to go straight into; to walk straight into