Dave Browne (43) from Castleknock had originally aimed to play for more than 100 consecutive hours but was told last night that the record actually stood at 113 hours.
The exhausted musician carried on, cheered on by a crowd of well-wishers to become a world record holder.
The loud chants of "Dave-o" attracted more and more passers-by at the Temple Bar pub this morning.
Dave started his world record attempt on Sunday and was scheduled to beat the original record by 8pm last night.
However, due to a mistake in the Guinness Book Of Records, he was told by organisers that he had to put in 14 more gruelling hours.
One of Dave's bandmates, Clare Peelo, was in tears as she described her pride for her friend.
"This was a dream of Dave's. He's so full of life. I'm unbelievably proud of him," she told the Herald.