AN ex-Royal Marine who knocked out a teenager with a single punch, leaving him with brain injuries and suffering fits, has been jailed for 20 months.

Callum Krzysik, 24, ranked second in the country for amateur mixed martial arts, attacked Nathan Hugill, an 18-year-old apprentice builder, in Burnley's Bar Code.

He then stood over his victim, shouting aggressively in his face while he lay unconscious on the dance floor and went on to shake hands with others clubbers.

Two off-duty paramedics offered medical assistance while an ambulance was called.

When a police officer was arresting the defendant, he drunkenly told him: "That lad deserved everything he got."

Krzysik afterwards tried to justify what he had done on Facebook, saying he wished he could put on the CCTV footage of the incident for others to view.

He had been just about to emigrate to Australia when he meted out the early hours violence, was desperate to go and offered cash and then 'anything' to his victim by proxy to try and get him to drop the charge, Burnley Crown Court heard.

The hearing was told Mr Hugill received multiple contusions to the frontal region of his brain, suffered two seizures, had to be prescribed anti-epilepsy medication and was not allowed to drive for seven months.

The defendant admitted inflicting grievous bodily harm last April 14 and attempting to pervert the course of justice. Krzysik, of Rosehill Road, Burnley, has previous convictions for breaking a victim's nose with a headbutt and being drunk and disorderly.

Prosecutor Nicholas Courtney said: " It would appear that the defendant is a young man who can't take his drink."

Mr Courtney told the court Mr Hugill's close friend, Poppy Kirkbride, was dancing with the defendant. He started to flirt with her, she felt uncomfortable when he asked for a kiss, didn't know what to do and looked towards the victim and another man, seemingly wanting their help.

Mr Hugill pushed the defendant aside and Krzysik squared up to him and took up a fighting stance. The victim stepped forward, with his arms down by his side and appeared to be neither about to attack nor anticipating attack.

The defendant then punched Mr Hugill on the left side of his jaw and the victim was immediately knocked unconscious by the force. He fell and banged his head on the floor. Mr Hugill was taken to the Royal Blackburn Hospital, with a large swelling over his left cheek.

A CT scan appeared normal, but the victim later returned to casualty after suffering two convulsions and a second scan showed multiple small contusions to the frontal region of his brain.

He was given medication to prevent further fits and discharged three days later. The prosecutor added: "The consultant stated significant trauma would be required to cause these contusions."

Mr Hugill also had a black eye, drowsiness, numbness, headaches and nose bleeds, was off work a month and then had to be put on restricted duties. He missed his final college exams.

Mr Courtney said Krzysik denied the offence when interviewed and was bailed. On May 23, Mr Hugill received two calls passing on messages from the defendant.

The prosecutor continued: "He was offered £300 in return for dropping the assault charge and immediately refused. The second message said he would give him anything to drop the charge. Mr Hugill again immediately refused the offer and told the police."

Daniel Lister, defending, said Krzysik accepted the seriousness of what he had done, which had been 'beyond foolish.'

Mr Lister said the defendant, a car salesman, had raised money for charity, including running for five miles in a mankini, and received a commendation from the Marines.

Sentencing, Judge Robert Altham told him: "There can be no justification for the level of force that you used upon him."