LOS ANGELES (AFP) - A woman accusing National Basketball Association star Derrick Rose and two friends of rape took the stand in her US$21.5 million (S$29.5 million) lawsuit against the New York Knicks guard, who arrived in court during her testimony.

The 30-year-old woman paused when Rose, wearing a black suit and diamond earring, entered the US District Court in Los Angeles.

She became emotional as she described Rose and two other men entering her apartment uninvited while she slept and taking turns sexually assaulting her.

Although her recollection of the alleged assault in August of 2013 appeared fractured, the woman said she remembers Rose "undressed ... at the edge of my bed," and Ryan Allen "on top of me" and Randall Hampton also "undressed ... near my bed".

She testified under questioning by her own attorney and is expected to be cross-examined by lawyers for Rose and the other defendants.

Rose has denied the allegation and has not been charged with a crime. His attorney Mark Baute has painted the lawsuit as a "fake case" in which the woman was seeking a "lottery hit" of a financial payout.

The woman alleges that after a night of drinking at Rose's rented Beverly Hills mansion she went home, but Rose and his friends came to her apartment.

When she awoke the next morning, she said her dress was in a knot around her neck and sexual lubricant was on her legs. An "open condom" was on the floor, she said.

"I was scared because I didn't know what happened," she testified.

The woman did not report the alleged incident to police until 2015.

Court documents show that Los Angeles police opened an investigation. Her lawsuit was filed in August of 2015.

Lawyer Michael Monico, on behalf of Hampton and Allen, had told jurors in opening statements on Wednesday that "there was no gang rape, there was no rape at all".

Rose, a former NBA Most Valuable Player with the Chicago Bulls, was traded to the Knicks this season after spending seven seasons with his hometown club.