TMZ.com reported Deanna Gines, 24, claimed Brown, also 24, deliberately shoved her to the floor in the VIP section of Heat Ultra Lounge where he had performed Saturday night. She said she landed on her knees so hard she tore ligaments and might need surgery, the entertainment news website said.
Gines said she complained to Anaheim police, who confirmed a woman filed a report for assault inside the club. TMZ said police wouldn't name the woman who complained but said the matter was being investigated.
TMZ said Brown tweeted, "I didn't do anything" and his representative, Nicole Perna told the website, "None of this makes sense."
The owner of Heat Ultra Lounge, who TMZ didn't identify, backed up the singer's tweet of innocence.
"Based on the information which we have gathered from our security company, mall security, and other party goers which were at HEAT on Saturday night; It is apparent that the alleged incident regarding Chris Brown is false," the owner wrote.
The owner said Gines had repeatedly tried to jump on stage during Brown's performance and later tried to rush him in his roped-off VIP area.
The owner said Gines was subsequently ejected from the club for her behavior and threw her shoes at security guards. He said police were called to arrest her, but she was eventually allowed to leave with friends.
"Heat staff and security did what they had to do. ... [Chris] was a complete gentleman," the owner said.
Brown has a history of violent behavior, including beating his girlfriend, singer Rihanna.