A woman on a night out in Stamford needed to have a head wound glued at hospital after being attacked by a Grantham man.
Shaun Dixon of Sturrock Court in Grantham had initially denied the charge common assault but changed his plea on the day of the trial to guilty.
The attack took place outside a nightclub in Silver Lane, Stamford.
Daniel Pietryka, prosecuting, told the court the assault was witnessed by a police officer who saw Dixon throw a “short, fast punch to the victim’s facial area”.
The officer restrained Dixon as he yelled “the f***ing b****, I’ve done nothing wrong”.
Mr Pietryka said the victim went to Grantham Hospital after the assault and “had to have her head glued back together as the cut was too deep to leave”.
Julian Sheen, defending, said there was an altercation outside the club “and, unfortunately, it became violent”.
He added: “All of the parties had been drinking, including the complainant.
“It got out of hand and, unfortunately, she came off far worse.”
Dixon, 22, was sentenced to a 12-month community order made up of supervision by the probation service and an alcohol programme.
Chairman of magistrates Peter Dolby told Dixon: “This should help your alcohol issues.”
He must also pay £150 to the victim and a £60 surcharge. Costs were increased to £250 due to the late change of plea.