A man had to spend four days in intensive care after being punched repeatedly while unconscious in an attack outside a working men's club.
A court heard the victim suffered horrific facial injuries in the drunken assault carried out by Gary Rodgers.
Rodgers, 57, was jailed for six years after pleading guilty to inflicting grievous bodily harm with intent in the incident outside the club in Upton, near Pontefract.
Carmel Pearson, prosecuting, said Rodgers and the victim were both drunk at the time of the incident on May 26 this year.
There had been a confrontation between the two men earlier in the evening,
Rodgers attacked the man when he was outside the club with his girlfriend.
He punched him to the floor and continued to strike him in the face when he was prone on the ground.
Rodgers carried on punching him despite attempts by the victim's partner and other members of the public to stop the attack.
The man spent four days in intensive care after suffering fractures to his facial bones and eye sockets.
He needed surgery to have metal plates fitted to his face.
The court heard Rodgers, of Wrangbrook Road, Upton, has previous convictions for violence.
He served a five-year prison sentence, imposed in 1996, for a similar offence.
Patrick Palmer, mitigating, said Rodgers had not committed offences for more than 20 years and was sorry for what he had done.
Mr Palmer said: "He was truly shocked when he came to discover the extent of the injuries he had caused this man.
"He is not proud or boastful. He is deeply ashamed."
Recorder Simon Kealey, QC, said: "It was a vicious and violent attack upon this prone and helpless man.
"It left all those involved covered in blood and you did not stop when asked to do so."