Three men have been given life sentences for killed an IT expert after snatching his girlfriend's Halloween hat.
Ben Gardner, 30, was punched to the ground where he lay helpless as one of the men kicked his head "as if taking a penalty".
Allanna Devine, 28, was also punched in the attack on October 31 last year, the Old Bailey heard.
Daniel Ransom, 21, Ross Collender, 21, and Jordan Dixon, 18, all of Carshalton, were jailed at the Old Bailey for the murder.
Ransom and Collender were handed a minimum 16 year prison term and Dixon was given 14 years inside.
Mr Gardner, who worked for insurance firm Legal & General, had been to a club with Miss Devine to celebrate her birthday and Halloween.
She was dressed in a pirate's outfit, with a black wig and hat. He had a black leather jacket and vampire fangs.
In the early hours of the morning, Miss Devine was waiting for Mr Gardner outside a kebab shop in Sutton when a group of men snatched her black hat and wig.
Miss Devine broke down as she spoke of Mr Gardner's last moments.
She said: "My hat and my wig were taken from my head. I was not concerned about it because it was the end of the evening, but I did say 'Can I have my hat back, please?'
"I was greeted by jeering. They were very loud." She was hit when she approached them.
Miss Devine added: "Ben decided he was not happy that my wig and hat had been stolen and he was going to approach the group about it."
Mr Gardner had said: "I am not a fighter but I have just seen someone hit my girlfriend and I am not standing back and letting you hit my girlfriend."
While he was dying, one of the attackers stood over him like a boxing referee and signalled him knocked out.
Mr Gardner died in the early hours of November 1 last year from "catastrophic brain damage".
Mr Gardner's father, David, said in a statement: "Ben died as a result of the actions of a group of thugs, who decided to attack him for defending his girlfriend after they had physically assaulted her and stolen her Halloween hat.
"I cannot forgive these people for what they have done. They have destroyed me and my family for the rest of our lives. I think the people that have done this should pay the ultimate price - death."
