Gardai are investigating a brawl involving dozens of football hooligans that sent a man to hospital with a split skull following a fight after the Shamrock Rovers and Bohemians match on Saturday.
The ugly incident erupted on Phibsborough Road at 5pm and brought traffic to a standstill.
A group of thugs ranging in age from their 20s to 40s could be seen throwing punches at one another as they wove in and out of parked cars and on to the road and pavement outside the local fire station.
Local Social Democrats TD Gary Gannon was driving by in a taxi and witnessed what he described as a "disgraceful act".
Video footage also captured the shocking scenes.
He took to Twitter following the incident, branding the participants "gobs***es".
"The people that were involved should be arrested and banned from the clubs," he told the Herald last night.
Driving conditions were poor enough due to very strong winds and heavy rain when the brawl broke out, he said.
"Initially it looked like 10 guys having a fight and very quickly there was up to 50," he said.
"It was really awful. There was a guy lying on the pavement with his head split open and blood pouring out."
Gardai confirmed that a man in his 40s suffered head injuries during the melee and was taken to the Mater Hospital.
The extent of his injuries are not known at this time.
The garda Public Order Unit was called to the scene to disperse the crowd.
No arrests had been made by last night but gardai said they had obtained CCTV footage.
Mr Gannon, a former Dublin city councillor who won the Dublin Central seat in the general election, said he was appalled by the mindless violence displayed by grown men.
"These were far from kids; these were guys in their mid-20s to late 40s," he said.
There did not appear to be any motive for the brawl following the derby between the two teams at Dalymount Park, he added.
"It was the very definition of hooliganism," he added.
The brawl appeared to have been organised by the participants following the match, which had a large security presence due to clashes with supporters from both sides in the past.
However, Mr Gannon said the brawl had no reflection on either club.
Officials from Tallaght-based Shamrock Rovers could not be reached for comment last night, but a spokesman for Bohemians said the club were reviewing CCTV footage and will ban any of the thugs identified from attending future matches.
"These people don't in any way represent the club," he said.