A pyjama-clad woman told how her partner looked "pure evil" in an attack which left her running onto an Ilkeston street to escape.
Ian-Hamilton Edmunds caused severe bruising, cuts, a black right eye and left her needing a trip to hospital, Nottingham Crown Court heard.
A one-year prison term, suspended for 21 months, was imposed on Edmunds, of Summerfields Way, Ilkeston.
He admitted assault causing actual bodily harm on August 26.
Lauren Butts, prosecuting, told the court that the couple had been together for three years and went into Ilkeston town centre for drinks on August 25.
They met some of her relatives, who gave him information and told Edmunds "they were on his side."
Miss Butts said: "She decided to go home and went to bed at 1am. She was woken by him punching her repeatedly in the face and head.
"She tried to get him to stop and get out of the house. He said 'you are a lying bitch.' She said he had a look of pure evil about him.
"She was trying to get away and he pushed part of her head through a glass window panel. The glass shattered and splintered.
"She ran out of the house in her pyjamas. He followed and assaulted her in the street. She ran to a house where a light was on and the occupant helped her," said Miss Butts.
When Edmunds was questioned by police officers, he recalled her relatives giving him drinks "to cheer him up, could not remember how much but did feel hazy," added Miss Butts.
Siward James-Moore, mitigating, said that Edmunds suffered a head injury in 2009 and that played a major part in this incident.
It harmed his memory and caused problems in understanding the effect of alcohol.
"When he is cooking a meal, it must take less than five minutes to cook or he will wander and burn it.
"He has in his house put up signs to turn off the lights, turn off the gas. He is not allowed to work because of his condition," said Mr James-Moore.
Judge James Sampson commented: "It doesn't stop him drinking though, does it?"
Mr James-Moore said: "He has a lack of appreciation and knowledge where that drink would lead him on that night."
He said that Edmunds does not have "a grudge" against the woman and told the court she wants to resume their relationship.
The judge ordered Edmunds to attend 25 sessions with probation officers, telling him: "This is to remind you not to drink, in effect.
"The injury was nasty and this was aggravated by your use of drink. You know about drink.
"Your father was an alcoholic and you are aware of that."
The judge added that the head injury "on the medical evidence seems to be a factor as well."