Osman Mahdi, 28, confronted 35 year-old Omer Jama Abdi when he stepped in to defend a female friend outside his flat in St John’s Road on February 14, 2012.
The Old Bailey heard witnesses saw him knock Mr Abdi to the ground with a single punch before returning a few moments later to kick him as he lay defenceless.
Mr Abdi, who had a severe heart condition, died in hospital the same morning.
When Mahdi, who lives in Kensington, was arrested a year later he claimed he punched the victim in self defence after being hit twice.
Last month he was convicted of inflicting grievous bodily harm with intent and cleared of both murder and manslaughter.