In 2015, Cosby was charged with felony aggravated indecent assault shortly before the statute of limitations on Constand's claim expired.
"She couldn't say no", Feden said. "They're your friends. They'll take the edge off", she quoted him as saying.
She told the jury she remembers that about 20 to 30 minutes later she had started slurring her words and could see double.
Cosby stared down at the defence table, resting a hand across his forehead, as Ms Constand testified.
Before Tuesday, Constand had never spoken about Cosby in public, barred from doing so under the terms of a confidential settlement they reached in 2006.
Johnson told a similar story in 1996, when she gave sworn testimony in a deposition attached to a worker's compensation claim.
Some 60 women have come forward to say Cosby sexually violated them, all but destroying his nice-guy image, but the statute of limitations for prosecution had run out in almost every case.
The stage was set for Tuesday's courtroom confrontation after prosecutors used the first day and a half of the trial to argue that Cosby made a habit of knocking women out with pills and then molesting them.
Miller testified that he recalled the woman mentioning Cosby during a deposition in the workers compensation case - "and that was a complete surprise". "And she had gotten semi-unconscious because of whatever she had taken, and that he had exposed himself to her and taken some of her clothing off".
The AP does not typically identify people who say they are sexual assault victims unless they grant permission, which Johnson has done.
Cosby, who is legally blind, listened intently to testimony on Tuesday but did not react to Sewell's account.
About 60 women have accused Cosby of sexually assaulting them since 1965, but Cosby is charged in just one case, involving a former Temple University basketball team employee who said he drugged and molested her at his suburban Philadelphia home in 2004.
Mason described Constand's demeanor as nervous but not upset as she spoke about the incident that occurred a year earlier. "But I knew I couldn't really get up and go anywhere at the same time, because my legs were rubbery, I was in no state of mind". She waited a year before reporting the encounter to authorities, and prosecutors at the time declined to press charges then due to lack of evidence.
Constand, an athletic 6-footer with colorful arm tattoos and a mane of dark curly hair, could face a bruising cross-examination from Cosby's lawyers, who have argued that the two had a romantic relationship, that she wasn't incapacitated and that the sexual encounter was consensual.
Pattrice Sewell says her daughter called her distraught in 1996, fearing Cosby was trying to get her fired from her job working for Cosby's agent. And, she said, her truth was to be at court and to be supportive. "She would go to work and come home, with no social life". "Her circle of friends became narrower".
Judge Steven O'Neill allowed the prosecution to bring Sewell to the stand to corroborate parts of Johnson's testimony given Monday, over the objections of Cosby's defense team. Johnson told jurors the visit happened before Cosby allegedly assaulted her. After that, Sewell said, her daughter changed.
The mother of a Bill Cosby accuser is telling jurors about the day her daughter told her Cosby had drugged her at a hotel bungalow.
Johnson testified Monday that she left the talent agency and did not return. She later woke up disoriented and partially clothed in Cosby's bed with the comedian behind her, grunting, before he forced her to touch his genitals, she testified. Cosby grinned at the defense table as she struggled to explain them. Johnson answered typical questions about where she lived, what medical treatment she received, and what typically caused her stress.
It wasn't immediately clear how soon she would take the stand.
McMonagle referred to what he called police's "exhaustive investigation", which initially ended with former District Attorney Bruce Castor's decision not to prosecute.
Cosby, 79, the champion of fatherhood and family values, walked into court on the first day of the trial Monday without his wife of more than 50 years, Camille, or any of their four daughters.
Joseph Miller, a worker's compensation lawyer who represented Johnson, says he was surprised by "things of a sexual nature" Johnson recounted during her 1996 deposition for her claim that she'd developed debilitating stress from her secretarial job at Cosby's agency.
Miller was the second witness called to help bolster Johnson's testimony Monday.