A young Sydney man is fighting for his life after being bashed in an attempt to help a taxi driver.
Police say the 19-year-old suffered critical injuries when a group of males were threatening a taxi driver in North Sydney about 2.15am (AEDT) on Friday.
The man was allegedly struck by one of the men and then kicked after he fell onto the roadway.
He suffered head injuries and was taken by ambulance to Royal North Shore Hospital where he underwent surgery.
He was placed in an induced coma and remains in a critical but stable condition.
Police say another man, 19, was arrested on Tuesday about 8am and charged with recklessly inflicting grievous bodily harm and common assault.
The alleged offender was granted conditional bail and is due to appear at Burwood Local Court on April 23.