An Edmonton man issued a tearful apology in court Friday to a father of two he severely injured when he stomped on his head in an unprovoked bar attack.

Dale Steven Carter, 28, cried as he told victim Scott Allnutt that he was "deeply sorry" for the 2012 assault that left the 45-year-old with a permanent brain injury.

"Nothing I can say can take that back," said Carter, calling the booze-fuelled incident his "waking point" as his girlfriend sobbed in the front row of the gallery.

"I'm sorry it had to be you," said Carter.

Carter earlier pleaded guilty to aggravated assault for the random Feb. 18, 2012, beating in the bathroom of Hudson's bar in South Edmonton Common which Provincial Court Judge Janet Dixon called an "incredibly violent assault" that resulted in "profound" injuries.

Crown prosecutor John Watson argued it is aggravating that Allnutt was attacked while he was on the ground and asked for a prison term of between five and seven years.

Defence lawyer Lionel Chartrand suggested a 21-month sentence - deemed already served by the 14 months he has spent in pre-trial custody - and two years of probation, arguing Carter was "extremely intoxicated" at the time and the attack was "impulsive" and "not planned."

Dixon is expected to sentence Carter on Oct. 1.

Court has heard Allnutt was at Hudson's celebrating his sister's birthday with family and was jumped by Carter in the men's room despite them having never met or spoken.

Watson told court Carter stomped on Allnutt's head when he fell down and said Allnutt never even had a chance to fight back as he lay bloodied on the floor. A witness got a bouncer and police and ambulances came shortly after.

Watson also told court that Carter's hands were covered in blood when he said to an officer: "It's not my fault the guy is in hospital. He should've fought harder. I'm just trying to have some fun."

Allnutt, who has no memory of the attack, was left with a severe brain injury. He spent two weeks in the University of Alberta Hospital and remains a patient of the Glenrose Rehabilitation Hospital. He suffers speech problems, mobility issues and numbness and has a spotty memory.

In a victim impact statement, Allnutt said his life "was changed forever" in an instant and he spoke about how his rehabilitative struggles have severely hampered his relationship with his two young children.

Outside court, Allnutt had mixed feelings about Carter's apology. "This will impact my family forever. It will never go away. This will never be over," he said.

Allnutt's wife Melissa said she felt Carter was sincere, but was "taken aback" by the defence arguing he should be let out on probation due to her husband having been given "pretty much a life sentence" by his injuries.

"I guess we'll find out Oct. 1," she said.