The Coal Exchange’s manager Dawn Swift was trying to sort a car in the Emsworth pub’s car park when she was grabbed and kicked.
Portsmouth Magistrates’ Court heard the group had been causing problems inside and outside the South Street pub.
Police were called just after 11pm on August 22 last year and the 41-year-old publican told an officer she was assaulted.
‘She said a group of youths approached her and started a fight,’ prosecutor Lucy Paddick said.
‘Miss Swift said there were approximately 10 males and three females involved.’
A ‘dark-haired male’ aged between 18 and 20 ‘kicked and grabbed her’ so ‘she punched him back’, the prosecutor added.
She added: ‘The officers spoke to a witness who provided footage of a female using a Taser on a male.’
When asked for the Taser, Swift said it was ‘gone’ but it was then retrieved from the car she was working on.
In court Swift admitted having a Taser, brandishing it, and putting it in a glovebox of the car she was fixing.
But Swift, who was said not to be interviewed by police, said she did not use it - and did not see anyone else do so.
Prosecutors accepted her basis of plea that she did not use it. ‘The crown can’t say who used the Taser,’ Ms Paddick said.
In her plea she said: ‘I showed it to a group of males to try and scare them from the public house but I didn’t use it on anyone.’
Swift is said to have significant mitigation that will be put forward when she is sentenced.
Adjourning the case, district judge David Robinson said: ‘The sentencing guidelines suggest that the starting point for the court’s consideration is a custodial sentence in this case.’
Probation will now compile a report on Swift, who was bailed ahead of the next hearing on September 23.
Police previously said a 40-year-old woman and three men aged 52, 23, and 18, had been assaulted in the incident.
Swift is not the pub’s licensee. She admitted possession of a Taser.