But just days after she went public with her allegations, police said CCTV footage of the incident told a different story.
"The version of events given by the 46-year-old female is not substantiated by this footage ... a decision has been made to prosecute [her] and a 43-year-old male," police said.
Maiden was due to appear in Manukau District Court on an assault charge this morning but the court today confirmed the matter had been heard yesterday, when she pleaded guilty to attacking Opai.
A sentencing date in March has been set but Maiden today told the Herald she had not pleaded guilty and the judge believed the stories were "twisted".
She said she was standing by her original version of events and would not comment further.
"I don't want to be in the media anymore. The news has embarrassed my children," she said.
A staffer at 123 Casino Karaoke Bar, who asked not to be named, told the Herald the incident happened as staff were cleaning up following New Year's Eve celebrations and they only reviewed the video footage when Maiden sought media coverage.
"The CCTV footage -- the policeman saw it himself -- and he goes, 'Oh yeah, her story's wrong'."
The footage showed Maiden speaking with a man who was smoking outside.
Words were exchanged, then she slapped him on the head. But the man did not retaliate.
The staffer said moments later Maiden was pictured punching the man.
"Then, I think, he couldn't take it from there."
"She punched him clean in the face and it pushed him back," the staffer said. "He stumbled backwards. The police watched it over and over again ... It was a big hit."
Opai will appear in Manukau District Court tomorrow on a charge of male assaults female.