For a mid-level gymnast from Kalamazoo, Michigan, who had back and wrist injuries, it was a special opportunity for her to see someone who was held in high regard by athletes in the sport.
That was in 2000. Nearly two decades later, Denhollander -- now an attorney, wife, and mother of three children -- was in court, telling a judge the doctor sexually abused her on five visits, right in front of her mother.
Nassar, who is accused of almost two dozen counts of criminal sexual conduct and has pleaded not guilty, sat in a black and white jail uniform Friday. During the preliminary hearing, he listened to his accuser and two other women who alleged years of repeated abuse.
CNN does not typically name people who are allegedly the victims of abuse, but Denhollander has publicly identified herself.
Denhollander recalled her first visit with the doctor, who was then also a professor at Michigan State University in East Lansing.
She said they agreed to do a massage technique called myofascial release therapy. She said she trusted him.
"He was the (1996) Olympic team physician. That's why I was there, because he could do things other doctors couldn't," the now-32-year-old said during more than two hours on the stand.
Nassar was 'revered," accuser says
The alleged sexual abuse, she testified, began in the first visit. Nassar put two fingers in her vagina, though she said she thought during the visit that it was intervaginal muscular work, a treatment she heard about from a friend.
Surely a national team doctor and an esteemed teacher couldn't be doing anything wrong, she recalled thinking at the time.
"He couldn't be a revered physician if he wasn't doing legitimate medicine," she said.
She left the appointment thinking that he had found things her previous doctors didn't. Feeling hopeful for the first time in a while, she thought Nassar was "very caring, very gregarious. He made you feel like he was going to take care of you."
She said she didn't tell her mother, who couldn't see the alleged abuse from where she was sitting, because "the idea that someone would sexually assault a child while (her) mother was in the room wasn't a classification that I had."
It was during her last follow-up treatment that Denhollander said Nassar unhooked her bra and rolled her on her side on the massage table. His hand went to her left breast.
"I froze, because I knew that was sexual assault," she said.
Nassar didn't speak in court Friday, the first day of the preliminary hearing. His lawyer, bound by a gag order, didn't speak to reporters afterward.
The hearing, which will continue May 26, will determine whether there is probable cause for a trial.
No discussion of doctor's techniques
Shannon Smith, Nassar's attorney, in cross-examining Denhollander, asked the former gymnast whether she agreed that the doctor had techniques different from other doctors.
"In terms of any question about the intervaginal procedures ... even the massage to the breast area you described, you never asked Dr. Nassar, 'Can you explain to me why you did that?'" Smith asked.
"I did not. I didn't want to draw any extra attention to it. I thought it was shameful enough," Denhollander said.
Denhollander's voice rose once during her interaction with Smith when she was being questioned about why she didn't speak up during her treatment, rather than 17 years later.
The former gymnast said she trusted the doctor's knowledge and experience.
"My presumption was he knew something I didn't know," Denhollander said.
The lawyer said: "And it's possible still that he knows something you didn't know with his training and expertise."
"No, ma'am," Denhollander said sternly.
Two other witnesses -- an adult woman and a girl -- also testified Friday that Nassar put fingers in their vaginas, according to The Detroit News.
When Denhollander found out the judge had ruled that a camera be allowed in the courtroom she asked the judge to turn one towards her as well.
She said she did not want Nassar to walk in feeling like he won, and while being cross-examined, she said, "I want him and I want the public to know that I know where the shame and the guilt for this lies. It lies on him and not on me, and I am not afraid of the truth."