The 47-year-old man is currently being treated at the Mater Hospital for serious injuries which were inflicted at around 10pm yesterday.
“He is very lucky to be alive considering that he was stabbed in the neck,” a senior source said.
A 40-year-old man who is the chief suspect in the case also required hospital treatment but he has since been arrested and is currently being detained by gardai at Store Street Station.
Sources say that both men are known to each other and are both also known to gardai for minor offences.
It is understood that they have had recent interaction with homeless and other support services.
The scene of the stabbing was sealed off by gardai this morning and officers are not looking for anyone else in relation to the incident.
A garda spokesperson said "Gardai in Store Street are currently investigating an alleged assault which took place this morning at 10pm on Thursday, January 6, on O’Connell Street in Dublin.
"The two men involved in the incident have since been taken to Mater Misericordiae Hospital where they received treatment for their injuries.
The stab attack happened as a Fine Gael TD welcomed the planned recruitment of 800 new Gardaí and 400 new civilian staff which he says will lead to a “dramatic increase” in-on the beat policing.
Deputy Neale Richmond has said that Operation Citizen has resulted in a drop in crime in Dublin and this practice of high visibility policing must be rolled out nationwide.
Deputy Richmond said, “After repeated calls for high visibility policing in Dublin, Operation Citizen commenced in October 2021, with over 100 Gardaí patrolling Dublin City Centre each weekend evening.
“Since the commencement of Operation Citizen, criminal activity in Dublin has significantly decreased.”
This initiative which began in October means than 100 gardaí will be patrolling Dublin streets at weekends to clamp down on anti-social behaviour and petty crime
“Thefts from persons are down 48pc, thefts from cars are down 25pc and public order offences have reduced by 11pc, all compared to the previous year,” he said.
“Clearly, high visibility policing is working and in order to continue this into 2022, Minister for Justice Helen McEntee has confirmed an additional 800 frontline Gardaí will be recruited this year, as well as 400 Garda staff. The Garda Mountain Bike Unit will also be expanded by 20pc.
“These additional recruitments will keep us on track to meet the target of 15,000 members of the Gardaí, and 4,000 Garda staff.
“The recruitment of additional Garda staff is crucial so that frontline Gardaí are not burdened with administrative work and can focus on their frontline duties. It is imperative that this recruitment drive results in more police working on the beat.
“With funding of €2.062 billion for 2022, An Garda Síochána have ample resources to continue Operation Citizen into 2022,” he explained.