Singer Cheryl Tweedy was "full of her own self-importance" at the time she was involved in a row which led to her being accused of a racial attack, a court heard.
Cheryl Tweedy never exploited her fame, her defence counsel said
The Girls Aloud star has denied attacking nightclub worker Sophie Amogbokpa, saying she only punched her because she had been hit first.
But the prosecution told Kingston Crown Court her "meteoric success" had not made her above the law.
The singer's defence counsel told the court Miss Tweedy had never used her celebrity to her advantage.
The charges against the 20-year-old singer, from Heaton in Newcastle, stem from an incident at the Drink nightclub in Guildford, Surrey, on 11 January.
Miss Tweedy is accused of having punched Mrs Amogbokpa and hurled racist abuse at her after the toilet attendant tried to stop her taking some lollipops.
But the pop star has told the court she always intended to pay for the sweets and had hit 39-year-old Mrs Amogbokpa in self-defence, after the club worker punched her in the face first.
On Friday the court heard closing speeches from the prosecution and defence.
'Too much, too young'
Prosecuting counsel Patricia Lees stressed nobody was above the law, however famous they were.
She suggested Miss Tweedy had lied about what had happened because she had "a lot of things riding on it".
Miss Lees said: "Even important or famous people can behave very badly indeed.
"Sometimes it is a question of having too much too young."
She went on: "What we do say is that on this occasion, intoxicated and full, I am afraid, of her own self-importance...she treated another woman extremely badly."
"Who do you think was behaving well or badly?
"The stone-cold sober lavatory attendant or the drunk Cheryl Tweedy who was frankly all over the place?"
'Total absence' of evidence
Speaking for Miss Tweedy, Richard Matthews said the singer had never used her fame to help her case.
He said: "Miss Tweedy's celebrity, small or large as it may be, does not assist you and has not been prayed in aid on her behalf, not once."
He said there was "a total absence" of evidence of Miss Tweedy making racist remarks from any witnesses, except from members of the club staff who had spoken with a PR agent the club hired after the incident.
Mr Matthews said allegations of racism had not even appeared in Mrs Amogbokpa's statements to police until she had met the agent.
He told the jury everyone had a right to defend themselves and that it was up to the prosecution to prove the singer, who sobbed in the dock as he spoke, had not acted in self-defence.
Miss Tweedy denies racially aggravated assault occasioning actual bodily harm and an alternative charge of assault occasioning actual bodily harm.
The trial was adjourned until Monday.