A man has suffered significant injuries following an alleged assault in Northgate overnight.

An 18 year-old man allegedly forced his way into a unit located on Allworth Street at around 7pm and assaulted the 71 year-old male resident.

The 71 year-old suffered serious head injuries after being struck multiple times.

He remains in hospital in a critical condition.

Police arrested the 18 year-old, who has since been charged with one count of grievous bodily harm and entering dwelling with intent by break.

He is due to appear in Brisbane Magistrates Court today.

Investigations are continuing.