Martha Kolleh-McBurrough caused controversy last summer when she said she put up the notice in her Yeanon cafe in Ossett, to ward off racist customers.
Three months later she was on the receiving end of a racist outburst by a woman who claimed she saw Kolleh-McBurrough bump her parked car outside the cafe.
Care worker Laura Mitchell, 25, stormed inside the cafe after a neighbour told her they had seen the owner causing the damage.
Mitchell, who was holding her three year-old daughter, called her ‘every name in the book, including black ‘b***h’ and threatened to slap her, magistrates in Wakefield were told.
Ms Kolleh-McBurrough said: “She was calling me all the names in the book. She was really, really angry.”
Mitchell, a mother-of-two who was seven months pregnant at the time, wept as she was convicted of making racially-aggravated threats.
She said she had only gone into the cafe to exchange insurance details with Kolleh-McBurrough who told her “you’re accusing me because of the colour of my skin”.
Mitchell, from Ossett, claimed that the owner stood there “right in my face, yelling and waving a spatula about in a threatening manner. She seemed very irate”.
Andrew Morris, who was eating in the cafe at the time, said Mitchell was aggressive and bigoted behaviour and he eventually told her: “There’s no need for racism”.
Prosecuting, Martin Sleight said: “The complainant came across as an honest and truthful witness who hadn’t come to court to make a malicious allegation against the defendant.”
Referring to the cafe owner’s controversial sign, he added: “She felt that people were racist towards her. I do not believe that people of Ossett are generally racist.”
Ben Tighe, for Mitchell, said she was of previous good character but added: “Racism cannot and must not be tolerated in our society.”
Mitchell was fined £485 and ordered to pay a #300 victim surcharge.