长驱直入

長驅直入
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

挺进迅速，锐不可挡。《水浒传．第一○七回》：「自此卢俊义等无南顾之忧，兵马长驱直入。」《荡寇志．第二一回》：「那厮若得了清真山，长驱直入，为患不小。」也作「长驱径入」、「长驱而入」。

重編國語辭典

挺进迅速，锐不可当

維基詞典

Entry Composition

1 长驱 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