A man will face court next month after he lashed out at police during an incident in Doonside on Wednesday.
Blacktown police were called to Scintilla Grove about 9.40pm following reports a Riverstone man, 39, was behaving erratically.
Police arrived soon after and found the man with an open wound to his hand and acting aggressively towards bystanders.
The man then allegedly aimed a blow at one of the officers who had tried to calm him down.
He was eventually subdued and arrested, before being charged with assaulting a police officer at Blacktown Police Station.
The man will face Blacktown Local Court on April 6.