NSW man dies after one-punch assault

A young man has died following an alleged one-punch attack in Sydney.

The 21-year-old had been at a house party in Minchinbury early Saturday morning when punched in the face.

The injured 21-year-old fell to the ground and lost consciousness.

He was rushed to Westmead Hospital, where he died at 6pm on Sunday.

The alleged attacker, also 21, was arrested and appeared in Parramatta Bail Court on the weekend.

He was refused bail to appear in Blacktown Local Court on May 7.

He is facing three charges including cause grievous bodily harm with intent.