Knicks star Derrick Rose began his rape defense case in a Los Angeles courtroom with bombshell testimony on Friday — calling a turncoat friend of his accuser to the stand to destroy her as a money-hungry, pathological liar.

The 30-year-old accuser “lies about everything that comes out of her mouth,” Rose’s star witness, Gabriela Chavez, told the federal jury that’s been hearing the sordid, $21 million civil case for two weeks.

Chavez, a former close pal of the accuser, is now playing for Rose’s side, telling jurors that two weeks after the alleged assault, the woman specifically stated she had not been raped.

The accuser did tell Chavez that she was “pretty upset” about her August, 2013 romp with the player and two of his pals — but only because she hadn’t heard from Rose since.

“I ended up asking her, are you saying you were raped?” recalled Chavez, a wellness consultant, of a conversation they had two weeks after the accuser alleges Rose and his two pals attacked her in her LA apartment.

“She said, ‘No, but I did have sex with all of them,’” Chavez recalled to the jury.

The two were dishing about the encounter while partying in Las Vegas, Chavez testified — and she showed the six-woman, two-man jury photographs of the two of them smiling at a nightclub, posing in white bathrobes and lounging poolside at the Aria hotel.

The accuser was in Vegas as the paid guest of “some friend she knew … a guy,” Chavez testified — and was having a great time.

“Did [the accuser] seem like her happy normal self?” Rose’s lawyer, Mark Baute, asked.

“Yes,” Chavez answered.

The accuser told Chavez that she was hurt by Rose’s nonchalant reaction to the group sex — implying that she’d failed to make the star player jealous, Chavez said.

“She specifically said, ‘Oh he didn’t even care that I slept with them.’ Those were her exact words,” Chavez said.

More recently, the accuser had confided that she hoped to settle her lawsuit against Rose and his two friends out of court, Chavez said.

Under cross examination by the accuser’s attorney, Waukeen McCoy, Chavez conceded that “the word consensual was never used” in their discussion about the incident.

Chavez also insisted she wasn’t seeking “money” for her testimony.

But she did reach out to Rose’s lawyer, because the accuser “was lying so much and making everything so messy and trying to scheme and get money from Derrick,” Chavez said.

“She lies to her family all the time,” Chavez said, looking directly at her former friend across the courtroom.

Rose’s attorney asked if the accuser was “a pathological liar” and Chavez answered without hesitation, “Definitely.”

Under re-cross, Chavez admitted that she was attracted to Rose and even had dinner with him in Beverly Hills in 2015.

‘She lies to her family all the time’

She was also asked by the accuser’s lawyer, McCoy, if she had sent a text to the accuser on Aug. 26, 2015, after her friend filed the civil suit against Rose.

The text read, “Hey girl. You ok? Was that you that filed or someone else it happened to?”

Chavez claimed she didn’t remember the text.

Prior to Chavez taking the stand, the accuser concluded her own side of the case, calling two powerful witnesses — a friend and her boss who testified that in the hours after the alleged assault, she’d made an immediate outcry that she’d been raped.

“She said she believed she was, you know, raped by three people,” the ex-boss, Tommie McCaster, testified.

“She actually told me she believed she was basically drugged and taken advantage of,” said McCaster, at the time ran an LA real estate firm.

The three men insist all of the sex — including at Rose’s rental house in Beverly Hills the night before — was consensual.

“Basically she was just saying that they had a lot to drink and she kinda blacked out,” the former boss remembered on the stand.

“She looked a little distraught,” he said. “She was a little uneasy. I would say typically not her silly self.”

He added, “She had some kind of wrap around [her hand] like a little Ace bandage wrap. She said she burnt it but she wasn’t quite sure how.”

That backs up testimony from the accuser’s friend, who told jurors Thursday that the woman was already so drunk earlier, at Rose’s home, that she grabbed scalding stones with her bare hands from a poolside fire pit in his yard.

Earlier Friday, accuser pal Marcela Carleo testified that about a week afterward, the woman said she’d been raped.

“She was vague in everything,” Carleo said, “but she told me specifically — what I remember are the words, ‘They came to the house’ and the word ‘rape’ was used.”

Carleo added, “She said she woke up and the room was in disarray. She said she found a bloody blanket and some condoms.”

Carleo also lent credence to the accuser’s claim that the three men either broke in or let themselves in to her apartment through an open door. Carleo said a side door to the complex was open “All the time” and that the accuser often left the door to the apartment unlocked.

The defendants counter that the accuser let them in.

Defense lawyers have spent the trial discrediting the accuser, who had dated Rose off and on in 2011 to 2013.

They’ve pointed to boozy, racy text messages shared by her and the player prior to the alleged attack and to the lack of forensics backing her claims, which came a full two years afterward.

But her former boss’s testimony helps the accuser — and hurts Rose — by showing that even though she waited to come forward publicly, she’d spoken of the alleged attack hours afterward to those around her.

Testimony by ex-roommate Claudia Carleo — Marcella’s sister — earlier Friday also hammered home that the accuser was disoriented and upset that morning.

At around 8 a.m. she “Came up to me and said, ‘Were there guys here last night?’” the roommate told the jury of a conversation in the apartment.

The roommie had seen Rose and his friends in the apartment hours earlier, but had thought nothing of it, she said.

“I looked at her confused and she said, ‘Did you know who they are?’”

Carleo’s testimony may have less weight with jurors, who have learned that she’d said in a May deposition that she should get paid $1 million for helping the accuser by testifying in the case.

The trial is due to wrap in the middle of next week.