A 13-year-old boy appeared in Highbury Corner Youth Court on Wednesday charged with murder after a verbal altercation escalated into a "shocking act of violence".
Christopher Barry, 53, was confronted by the teenager along with a group of youngsters, as he attempted to gain entry to his home in Edmonton.
Police said he was followed into the building by two of the boys and stabbed.
Ambulance crews attended but he was pronounced dead at the scene shortly before 8.40pm on Sunday.
Detective Chief Inspector Neale Baldock, said: "Our initial inquiries have established that there was a supervised party taking place at another address within the block and the group of males were trying to gain access to this.
"The victim and this group were not known to each other - what started as a minor verbal altercation has escalated into a shocking act of violence."