Human rights lawyer George Bizos was recovering well from surgery at Milpark Hospital in Johannesburg, The Star newspaper reported on Wednesday.
"He is fully awake and there have been no complications. Our biggest struggle will now be to keep him in bed for the next few days," said his son, Damon Bizos.
Bizos, 80, had a "subdural haematoma", a form of traumatic brain injury where blood gathers in the outer protective covering of the brain.
Medication possible cause
It may have been caused by hypertension medication.
A neurosurgeon drilled two tiny holes into his skull on Tuesday to drain the blood that collected between the surface of the brain and the brain's outermost covering.
"He was positive [about the surgery]. He knew he had to have it and he was prepared," said his son.
Bizos is expected to remain in the intensive care unit at Milpark Hospital for at least two days before he would be moved to a general ward. He was admitted to hospital last week.
Bizos made his name as a human rights lawyer during the apartheid era. He defended Nelson Mandela, Govan Mbeki and Walter Sisulu in the Rivonia Treason trial.
Although now retired, he is a presidential appointee to the Judicial Service Commission. – (Sapa, June 2009)
Richardson's diagnosis confirmed
Head injury=loss of brain tissue