The incident happened in the early hours of this morning.
A man is in a critical condition in a Dublin hospital after a serious assault in the capital.
It happened at around 2.30am at the junction of D'olier Street and Fleet Street.
Gardai and emergency services were called to the scene in the early hours and found a man in his 20s with serious injuries to his head.
He was immediately rushed to St James' hospital, where he remains in a critical condition today.
During a follow up operation a house was searched under warrant in neighbouring Kildare, a man in his 30s was arrested in connection with the attack.
He's being held at Pearse Street Garda Station in Dublin.
Investigators have completed a forensic examination of the scene at the end of Fleet Street, and are appealing to the public for information.
Officers are particularly interested in speaking to anyone who has video footage from dash cams, and that can be presented to Pearse Street Station.

Kfm Obituary Notices
Damaged Water Mains In Maynooth To Be Replaced, With Works Commencing Next Week
Planning Approved for €260m Expansion of Newbridge Brewery
€100,000 Spent Repairing Historic Kildare Canal Bridge After Repeated Crashes
Boost for Special Education in Kildare—But Gaps Remain
Uisce Éireann Commencing Next Phase Of Work To Supply New Water Main In Two Mile House
Completion Date For The New Children's Hospital Will Be Missed For The 18th Time