Man dies in hospital after Sydney assault

A man has lost the fight for his life five days after he was seriously injured in an assault in Sydney.

The 55-year-old was rushed to St Vincent's Hospital on Thursday after he was assaulted in Darlinghurst but died in hospital, police said on Tuesday.

Police say he was walking along Crown Street when a man unknown to him allegedly punched and kicked him in the face.

He was taken to hospital with multiple skull fractures and died on Tuesday.

A 34-year-old man charged with the assault will appear at Central Local Court on November 17.

His charge of recklessly causing grievous bodily harm is expected to be upgraded to murder, police say.