A man had part of his earlobe bitten off in an attack on three staff at a north Belfast off-licence.
A 21-year-old man has been charged with grievous bodily harm with intent, possession of an offensive weapon, attempted robbery and criminal damage following the incident on Saturday night.
An intruder entered the Wineflair store at around 7.40pm and then grabbed a female member of staff and put her in a headlock.
He demanded cash before being tackled by two male employees.
The PSNI said that it was during the struggle that the would-be robber bit off part of the male worker's ear.
"The intruder was then restrained by a male customer until police arrived a few minutes later," it added.
Police are urging the have-a-go hero to come forward, having departed the scene shortly after officers arrived.
"This customer left the store a short time after police arrival and we are appealing for him to get in touch with us on the 101 number," the PSNI said.
DUP councillor Dale Pankhurst hit out at what happened.
"This is an utterly despicable incident and I wholeheartedly condemn it," he said.
"It should never have happened and my thoughts are with all the staff involved."
He urged anyone with information to contact police.
SDLP councillor Paul McCusker condemned the incident on social media yesterday.
"Disgusting attack on staff at the Wineflair on the Antrim Road last night," he wrote on Twitter.
Mr McCusker praised the employees and customer who restrained the attacker as "very brave".
"I've spoken to staff today, who are very clearly shaken up, and I wish the injured staff member a speedy recovery," he added.
Police confirmed that the suspect is due to appear at Belfast Magistrates Court this morning.