Bill Cosby's lawyers turned to their star witness in the comedian's sexual assault retrial, countering the harrowing accounts of a half-dozen accusers with a woman who says chief accuser Andrea Constand mused about framing a celebrity in hopes of a big payday.

Temple University academic adviser Marguerite Jackson took the witness stand the same day jurors heard Cosby's explosive deposition testimony about giving quaaludes, the since-banned 1970s party drug, to women before sex.

As the trial entered its ninth day Thursday, Cosby's lawyers lost their fifth bid for a mistrial over the prosecution's treatment of Jackson.

The defense argued prosecutors were out of line for implying they were wrong to help Jackson write a statement outlining her claims about Constand. Prosecutor Stewart Ryan irked Cosby's lawyers during Jackson's cross-examination on Wednesday by repeatedly saying they "created" her affidavit.

Ryan highlighted differences between the Jan. 22 affidavit and one that Jackson wrote on her own last year, getting Jackson to concede that Cosby lawyer Kathleen Bliss had her add quotes and make other changes to the second document.

Judge Steven O'Neill said there were "simply no grounds for a mistrial" and that Cosby's lawyers were raising the issue too late. He added that it didn't appear the defense did anything wrong, nor were prosecutors wrong to question their involvement.

O'Neill was upset that Cosby's lawyers had just one witness ready to testify on Thursday — a drug expert who will take the witness stand after prosecutors call their own drug expert.

District Attorney Kevin Steele also expressed his displeasure and wanted O'Neill to make sure sequestered jurors weren't blaming prosecutors for wasting their time.

"Are you going to tell the jury that it's their fault?" Steele asked the judge.

"My fault. No. Their fault? Yes," Cosby lawyer Tom Mesereau retorted.

"This court is not about blame," O'Neill said. "Just pack your witnesses in."

The prosecution expert expected to take the stand Thursday, Dr. Timothy Rohrig, testified at Cosby's last trial that wooziness and other effects Constand described could have been caused by quaaludes or Benadryl, the over-the-counter cold medication Cosby claims he gave her.

Quaaludes have been illegal in the U.S. since 1982.

Cosby, in the 2005 deposition read to jurors by a police detective, said he used quaaludes "the same as a person would say, 'Have a drink.'"

"Quaaludes happen to be the drug that kids, young people were using to party with, and there were times when I wanted to have them just in case," Cosby said in the deposition, given in 2005 and 2006 after Constand sued him.

Cosby's testimony was hidden from public view until The Associated Press petitioned to have it unsealed. That led prosecutors to reopen the criminal case and file charges.

After jurors heard Cosby's quaaludes testimony, the defense put Jackson on the stand. She testified that Constand, Temple's women's basketball operations director, spoke to her on a February 2004 road trip to Rhode Island about fabricating sexual assault allegations against a high-profile person so she could "get that money" from a lawsuit.

After watching a TV news report about a celebrity who had been sued over allegations of sexual assault, Jackson said, Constand told her: "Oh, wow, something similar happened to me." Constand said she never reported the assault because her assailant was a "high-profile person" and she knew she couldn't prove it, Jackson testified.

Jackson, who said she roomed with Constand on the trip, told jurors that she encouraged Constand to come forward. She testified that Constand then switched gears, saying, "No, it didn't, but I could say it did. I could say it happened, get that money. I could quit my job. I could go back to school. I could open up a business."

Jackson's account was immediately challenged by prosecutors, who suggested she was not on the trip on which she says her conversation with Constand took place.

Jackson's appearance on the witness stand was one of the most highly anticipated moments of a retrial that has Cosby, 80, defending himself against criminal charges that he knocked Constand out with pills and then sexually assaulted her at his suburban Philadelphia home in 2004. Cosby paid Constand nearly $3.4 million in 2006, and his lawyers call her a "con artist" who set him up.

Jackson said a comedian she met on a cruise put her in touch with Cosby's lawyers in November 2016. They got to talking about Cosby after the comedian offered to buy her a drink and promised, "I won't put anything in it," she recalled.

O'Neill blocked Jackson from taking the stand at Cosby's first trial last year, ruling her testimony would be hearsay after Constand told the jury that she did not know her. That trial ended without a verdict after jurors deadlocked. The judge changed his mind about Jackson for the retrial, giving the defense case a huge boost.

The Associated Press does not typically identify people who say they are victims of sexual assault unless they grant permission, which Constand has done.