She's the one person defense lawyers hope can single-handedly sink the sexual-assault case against Bill Cosby.

And as she testified for the first time Wednesday, Marguerite Jackson quickly got to the point.

The Temple University academic adviser recalled a conversation she says she had with Andrea Constand in 2004 – one in which she says Cosby's chief accuser spoke of fabricating her abuse claims to extort a celebrity.

"I asked her … 'Did this really happen to you?' " Jackson told jurors. "She said: 'No, it didn't, but I could say it did. I could quit my job. I could get money. I could go back to school and open up a business.' "

That purported statement by Constand – nearly a year before she reported that Cosby had drugged and assaulted her — lies at the heart of the defense case the comedy icon's lawyers began presenting Wednesday.

Defense lawyer Tom Mesereau has sought since opening arguments to paint Constand as a gold-digging opportunist who framed Cosby for the $3.4 million civil settlement he ultimately paid her.

Constand has maintained the conversation Jackson describes never took place – an assertion that prompted Montgomery County Judge Steven T. O'Neill to bar Jackson from testifying at Cosby's last trial in June.

But the judge reversed his decision for the retrial — and the defense wasted no time Wednesday in calling its star witness to the stand in Norristown.

Testifying on the claim for the first time, Jackson spoke in an assured tone, her head often cocked to the side. She insisted she had shared a hotel room with Constand in February 2004 when the two traveled to Rhode Island with the Temple women's basketball team – a team that employed Constand as an operations manager at the time.

As Jackson recalled it, a news report came on the TV about a famous person besieged by sexual-assault claims, and Constand said something similar had happened to her.

"I was like, 'Really? Who? When?' " Jackson told jurors.

She said she urged Constand to report it, but Constand insisted she couldn't because her assailant was a "high-profile person" and she knew she couldn't prove the allegation.

It was only after asking three times, Jackson testified, that Constand admitted it didn't happen — but said she could make it up and say it did.

Her account contradicted Constand's own testimony. On Monday, Cosby's accuser had told jurors she "remembered a Margo" at Temple but insisted that they never shared a room.

Jackson acknowledged that she heard Constand had tried to press charges against Cosby and sued him in 2005 but she said nothing at the time. She was convinced to come forward, she testified Wednesday, after discussing the case with a comedian she met in late 2016 who put her in touch with Cosby's lawyers.

Assistant District Attorney M. Stewart Ryan seized on that moment in his cross-examination, suggesting that Cosby's lawyers had shaped Jackson's testimony to suit their case. He questioned Jackson with a dismissive and scoffing tone.

"Did Ms. Constand tell you that as part of her master plan, that the person she would accuse would later admit to giving her pills that incapacitated her?" he asked. "Did Ms. Constand tell you … that the person she would accuse would admit to the sexual contact?"

But Jackson remained unruffled and soon ceded the witness stand to a string of quick defense witnesses who included Cosby's private chef and Charles Kipps, a writer who worked with Cosby on projects like the mid-1990s TV show The Cosby Mysteries and the 2004 Fat Albert movie.

Earlier in the day, prosecutors all but wrapped up their case – one Montgomery County District Attorney Kevin R. Steele presented over eight court days featuring testimony from five Cosby accusers, in addition to Constand.

Among the final prosecution witnesses was famed celebrity book editor Judith Regan, called to bolster testimony from supermodel Janice Dickinson.

Dickinson had testified last week that Cosby knocked her out with a pill and then raped her during a 1982 trip to Lake Tahoe. But Cosby's lawyers confronted Dickinson with her own 2002 memoir, No Lifeguard on Duty, in which she wrote about her meeting with Cosby but made no mention of her alleged assault.

On Wednesday, Regan, who also published O.J. Simpson's 2002 tell-all, If I Did It, assured jurors that Dickinson wanted to recount the alleged rape in the book but that she persuaded the supermodel not to include it, for fear Cosby would sue them.

"I insisted we leave it out," she said. "She was very angry about that and she was angry over a period of time."

When the trial resumes Thursday, both the defense and prosecution are expected to call forensic drug experts to the stand.

Keep up with every development in Bill Cosby's case with our day-by-day recapstimeline, and explainer on everything you need to know about the case and its major players.