Jade Defoe, 26, was a rapper and father-of-three
The half-brother of footballer Jermain Defoe died "tragically" after suffering brain damage when he was punched to the ground, a court has been told.
Jade Defoe, 26, was attacked in a row with Christopher Farley in Newham, east London, the Old Bailey heard.
The rapper and father-of-three, known by his middle name Gavin, died in hospital four days after the assault in April 2009.
Mr Farley, 34, of Kingswood Road, Leytonstone, denies manslaughter.
Mr Defoe also sustained a fractured skull after he was knocked unconscious and he was unable to break his fall, jurors were told.
"What led to Gavin Defoe's death started as an argument which had developed between him and the defendant, as a result of which this defendant was to punch Gavin once, hard to the left side of the face, with a clenched fist," said Brian Altman QC, prosecuting.
"The blow felled Gavin to the ground.
"It is highly likely that the force of that punch was such as to render him unconscious because it is perfectly clear that Gavin's fall was unprotected.
"The impact by his head on the ground was so heavy and severe that his skull fractured and he suffered severe brain injury from which he was to die."
Mr Defoe began to suffer fits and was taken to Whipps Cross hospital in east London before being transferred to the National Hospital for Neurology and Neurosurgery in Queen Square for specialist treatment, where he died.
Mr Farley said an argument started in which he accused Mr Defoe of breaking into his house, the jury was told.
"He said it wasn't meant to hurt him but to wake him up because Gavin thought he was joking and he was now being serious," said Mr Altman.
"He said he hit him on the bottom of the chin and his eyes started flickering and then his arms went straight, and then he fell straight back, hitting his head hard on the floor.
"His head bounced back up and then went to the side."
A 13-year-old girl who was in her mother's bedroom at the time Mr Defoe was assaulted heard swearing and a man calling him a "prick", the court heard.
Ambulance staff found Mr Defoe "agitated" and in a "confused state", and he began to fit before being taken to hospital.
A blood sample showed that he had used some cannabis but no trace of alcohol or any other drugs were found, Mr Altman told the jury.
The court heard that both sides agreed that Mr Farley attacked the east London rapper but the defence will argue that "medical negligence" led to his death.
Mr Altman said while there may have been "shortcomings" in Mr Defoe's treatment, for instance delay in transferring him for specialist treatment, Mr Farley's role cannot be discounted.
Farley also told police he had a "bad temper" which he had been trying to curb, the court heard.
He was heard by a prison officer saying during a telephone call: "I did it - just one of those things," the jury was told.
The case continues.