A 25 year old man has been arrested in connection with an assault in Waterford City in the early hours of yesterday morning.
It happened at the corner of John Street and the Manor at around 3.00am.
A 27 year old man sustained head injuries and remains in a serious condition at Cork University Hospital.
Gardai arrested a 25 year old local man shortly after noon today (Sunday).
He is being detained at Waterford Garda Station under section 4 of the Criminal Justice Act.