The celebrity cook told the court she had been “put on trial” over false allegations of drug use and had endured a “summer of bullying and abuse”.
Ms Lawson told the court the “awful incident at Scotts [restaurant]”, when Mr Saatchi was photographed holding her by the throat, was followed by false allegations of drug use against her on a “PR blog”.
“I have been put on trial here where I am called to answer, and glad to answer the allegations, and the world’s press, and it comes after a long summer of bullying and abuse.
“I find it’s another chapter in that.”
Ms Lawson, dressed in an all-black outfit, admitted she had been reluctant to give evidence in the trial, and spoke of her ex-husband’s reaction.
“He had said to me if I didn’t get back to him and clear his name he would destroy me,” she said.
Ms Lawson said the allegations on the blog were “dedicated to salvaging Mr Saatchi’s reputation and destroying mine”.
Asked Ms Lawson if Mr Saatchi had a temper: “Yes, he did have a temper and I don’t think that anyone can be in any doubt he had a temper,” she said.
Asked if Mr Saatchi was patriarchal and traditional, Ms Lawson claimed he “didn’t like to take part in family life”.
Questioned by Mr Metzer about whether she thought Mr Saatchi’s background conflicted with hers, she replied: “I don’t understand why my marriage is pertinent to you.”
Ms Lawson, who stood for the entirety of her evidence before lunch, said while her late husband, John Diamond, left some debts, she did not use Mr Saatchi’s money to pay them off.
“I’m an independent woman and I used none of his money to pay off my husband’s debt,” she said.
Ms Lawson, 53, added that her independence could “irritate” Mr Saatchi.
Mr Metzer asked whether Ms Lawson “confided” in Lisa about Mr Saatchi’s temper.
“Yes,” she replied.
The barrister then asked whether Ms Lawson discussed with Elisabetta Grillo that she was contemplating leaving her then-husband.
“It wasn’t so much a discussion,” she said. “I may have said I didn’t know how much longer I could take this.”
Mr Metzer said: “You confided in Lisa that Mr Saatchi had been shouting and swearing at you?”
Ms Lawson replied: “I think she may have even heard some of it, yes.”
Mr Metzer asked the food writer whether Lisa confided in her that Mr Saatchi had shouted and sworn at her too.
“I have to say it was not beyond impossible to imagine. But I don’t remember any such confidence. I remember her saying he’s very much like my father.”
She told the court that Mr Saatchi wanted at least one of the sisters to be working, but the pair were both given time off over the Christmas period.
“I did explain to him that it was Christmas,” she said.