A former London Zoo zoologist has been found guilty of glassing the ex-girlfriend of her llama-keeper lover during a Christmas party fight.
Caroline Westlake, 30, assaulted monkey-keeper Kate Sanders after being confronted about dating Adam Davies.
However, Westlake claimed Ms Sanders punched her in the face first, and that she struck out with the glass accidentally.
She told the court she did not remember hitting Ms Sanders with the glass, but accepted that she may have reacted with it in her hand due to her dyspraxia and ADHD.
During the Christmas party on the night of December 8 last year, Westlake heard Ms Sanders saying to friends in the toilets, "have you seen the state of her?".
But the feud came to a head at the end of the night when Westlake went to the cloakroom and Ms Sanders approached her after the party in the Prince Albert Suite at London Zoo.
Describing the incident, Westlake said: "When I got to the cloakroom I remember looking up and seeing her standing there."
She added that she felt a bit uncomfortable after hearing the comments earlier in the night, but did not want to leave and give the impression that she was "terrified".
Westlake continued: "She (Ms Sanders) said 'Caroline, I want to apologise for what you heard me saying earlier in the bathrooms', and then I remember saying 'why did you say it? I am trying to be nice, trying to be civil, I don't understand what I have done wrong to you'.
"And then I remember her saying 'you're dating my ex-boyfriend'."
Westlake had been seeing Mr Davies for a year at the time, and he had previously had a five-year relationship with Ms Sanders.
Westlake told the court that soon after she and Ms Sanders started speaking, the argument escalated.
She said: "It got really, really heated and she was saying everyone hates you, everyone says you're mad, no one likes you. She just kept screaming in my face. So then I said 'they say the same about you'.
"She punched me in the side of my face. It kind of knocked me, knocked me back. And then it was like a split second struggle and I was standing apart from her and I remember seeing her face was cut, and I remember thinking 'how has this happened?'," she added.
The bench at Westminster Magistrates' Court heard that Ms Sanders had a history of hitting people.
Giving evidence, Mr Davies described how she had slapped him after a football World Cup match between England and USA in 2010.
He said that Ms Sanders had commented that England were rubbish and had started to sing the Australian national anthem, when he asked her not to.
"And then she slapped me across the face," said Mr Davies.
He added that it was "not playful".
Mr Davies said he had not seen the fight between Westlake and Ms Sanders, but that the former had been hanging around him a lot more than usual that night.
He said: "Kate had been spending a lot more time around me than she had previously.
"I would say she was being more flirtatious than normal. She was just dancing around, pretty close. She was just chatting to me more than normal.
"And there was an incident ... She was like stroking my tie."
Westlake, of Salisbury Road, Banstead, Surrey, denied one count of assault. She is due to be sentenced on October 14.
Speaking outside court, Westlake's lawyer, Suzanne Kelly, said: "The bench found the charges proven, they said it was not intentional but it was reckless by virtue of having a glass in her hand and by being in close proximity to someone.
"It is my view that the bench were wrong in their interpretation of the law and recklessness, and for that reason, we will be appealing."
Westlake and her group of supporters tussled with photographers as they left the court building.