Chris, now 28, recalls he had been celebrating a Warriors rugby league win on the day his father, a once fit and healthy police officer, suffered the life-threatening injuries.
"Entering the hospital room and seeing my dad lying in an induced coma, with his eyes swollen shut and tubes everywhere was definitely the most devastating thing I have seen."
Chef Patrick Ikinofo was charged with assault but the charges were dropped, in part because Wayne Harris could not remember what had happened.
Electrician Chris said he struggled to tell his dad he had been given only a few years to live.
"He did not fully understand which was quite upsetting for me. However as time went on Dad now understands and we now take strength from each other as we are both suffering in different ways."
Chris quit his electrician business at the start of this year as the illness took hold.
Meanwhile, Wayne has been in rehab clinics and hospitals and relies on the support of his partner Sarah Murray and two daughters Nicola and Kimberly.
Ikinofo has worked as a chef in London and now Dubai.
Chris Harris said: "The person who assaulted my dad was already on bail for a previous incident, he was meant to be at home the night he punched my dad because of his curfew, he did not get punished at all for assaulting my dad."
The bleak prognosis led the family to seek alternative treatments.
Wayne's partner Sarah discovered the NeuroPhysics Functional Performance Training and Rehabilitation in Australia and the family are trying to raise $45,000 for both father and son to travel to Australia.
"Having struggled for such a long time this is incredibly exciting news for us and it gives us a little bit of hope."
The founder of the NeuroPhysics clinic, Ken Ware, said his research had been peer reviewed and presented at neuro science conferences and universities around the world.
He had helped a paraplegic to walk again, and been featured on Australian current affairs shows.
Auckland Brain Injury Association manager Stephen Jenkins said it was unusual for a treatment to cost in the tens of thousands of dollars.
To donate, go to www.givealittle.co.nz/cause/afatherandsonsbattle