Jack Boehm feared for his life as he laid pinned to ground on the side of a rural road, being punched multiple times to the face in a road rage attack.
Bright man Ben Hill has now been taken into custody over the assault after a magistrate rejected his "inconsistent" claims of innocence.
After a two-day hearing at Wodonga Magistrates Court, he was found guilty on Wednesday of intentionally causing injury, throwing a missile and reckless conduct endangering serious injury.
Barrister Fabian Brimfield conceded a jail sentence was inevitable.
Mr Boehm - who was travelling from Bairnsdale to Yackandandah with his sister for their Nan's 75th birthday dinner - gave evidence that after passing Hill's car on Great Alpine Road, he slowed to 30km/h to make the point that the man had left his high beams on while driving behind.
That sparked some cat and mouse between the pair.
Hill pulled over at one point and waited for Mr Boehm's car to come along, before throwing a full can of Carlton Draught beer - but he missed.
Further along, on Carrolls Road in Rosewhite, he was tailgating Mr Boehm and ran into the back of his car when the victim braked suddenly to avoid three deer in the middle of the road.
That is when the physical fight started and Hill pinned Mr Boehm to the ground before punching him multiple times to the face, causing severe bruising and swelling.
He was left in what he described as "immense physical pain" after the attack.
In his victim impact statement read to the court, Mr Boehm said he has been left with a permanent scar above his right eye, ongoing anxiety and difficulty sleeping.
"It's a constant reminder every time I look in the mirror," he said. "I feel extremely traumatised, and constantly anxious and scared."
Magistrate Ian Watkins said he did not accept the variety of excuses Hill used during his evidence, including that he only threw punches over his shoulder while the victim had him in a headlock.
"The injuries sustained by Mr Boehm are wholly inconsistent with the version of events detailled to the court by the accused," he said.
Hill said Mr Boehm had driven behind him with high beams on first and he acted in retaliation.
He claimed he had concussion from the crash when his head hit the steering wheel and the victim had actually punched him first.
"I wanted to get him off me, I felt like I was in danger," he said.
Mr Brimfield said Hill was diagnosed in 2013 with serious mental health issues including symptoms of schizophrenia and alcohol abuse disorder.
Hill was immediately taken into custody, but his sentencing was adjourned until August 14 while an updated psychological report is conducted.
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