HONG KONG — Life imitated art, startlingly and crudely, in the city of Hai’an, north of Shanghai, when two men rushed the stage and groped the painter and performance artist Yan Yinhong as she danced “One Person’s Battlefield” — her furious comment on sexual violence against women.

The assault continued through her entire performance as she dodged the men who kissed and groped her, grappled her to the floor and thrust their hands up her skirt, the audience making only halfhearted efforts to help as they stood by and recorded the incident with phones and cameras.

Did she report it to the police? No: “How could you report that here?” she asked.

“To me, their interference showed the vileness of society, and our society is vile,” Ms. Yan said in a telephone interview.

It was “real embarrassing,” said Cheng Meixin, an independent art critic and curator and the organizer of the Hai’an China Contemporary Art and Ideology Forum, where the incident took place in mid-June. “It should never have happened,” he said. One of the men — both are Beijing-based artists known to Mr. Cheng — had “psychological problems,” he said.