Bill Cosby at the Montgomery County Courthouse in Norristown, Pa., in May. (Pool photo by Matt Rourke/European Pressphoto Agency)

A woman who alleges that she is the first known sexual assault victim of Bill Cosby is withdrawing her defamation lawsuit against the comedy legend.

The decision by Kristina Ruehli, who says Cosby drugged and assaulted her in 1965, was made despite the fact that she had just won a significant victory in her case. On Thursday, a Massachusetts federal judge had blocked Cosby’s attempt to have Ruehli’s case dismissed, a ruling that would have allowed the case to proceed.

But Ruehli, in an interview with The Washington Post, said she felt that she had already succeeded in the goal of drawing attention to and bolstering her allegations against the comedian, who has also been accused by more than 50 other women of rape, sexual assault or sexual harassment. A previously undisclosed deposition for her case includes testimony from a former boyfriend of Ruehli’s who said she told him about her sexual assault accusation within days of it allegedly taking place in 1965.

The withdrawal of Ruehli’s suit lessens slightly the legal pressure on the 78-year-old comedian, but he still faces half a dozen civil lawsuits filed by other accusers, as well as a criminal case in Pennsylvania, where he is accused of drugging and sexually assaulting a former Temple University women’s basketball official, Andrea Constand.

“I do not want Cosby’s money, as I have wealth of my own,” Ruehli said. “And, at age 73, it’s a little too late for celebrity.”

Ruehli, who says she spent $80,000 of her own money on the defamation lawsuit, was one of a dozen anonymous “Jane Doe” accusers in a lawsuit filed by Constand in 2005. “No fame or fortune was involved in that,” she said.

“This is now the second of these defamation cases that has been dismissed, either by a Court or by a party,” a Cosby spokesman said in a statement. “We hope and expect that there will be more, and we look forward to fighting any that are not dismissed, before a jury of our peers. For those in the media who accepted every allegation raised without question or evaluation, they need to answer the well-known question with respect to Mr. Cosby, ‘Which office do I go to get my reputation back?’ ”

Ruehli was 22 and working as a secretary at a Los Angeles talent agency in 1965, when she says Cosby invited her to a party at his Los Angeles home. When she arrived, Cosby’s home was nearly empty. He gave her two drinks, she says, and she passed out. Later, she awoke naked in Cosby’s bed, with the comedian attempting to force her to perform oral sex on him.

Ruehli sued Cosby because of statements made by the comedian’s attorney in 2014 amid a storm of news coverage about allegations of sexual assault and drugging. Martin Singer, who was Cosby’s attorney at the time, said: “The new, never-before-heard claims from women who have come forward in the past two weeks with unsubstantiated, fantastical stories about things they say occurred 30, 40 or even 50 years ago have escalated past the point of absurdity.”

After Singer made the statement, Ruehli said, looking back, “I felt like I had a big red ‘L’ [for liar] painted on me, and I needed to remedy that through the judicial system. With this lawsuit I have managed to wash some of the ‘L’ off and regain my reputation.”

Ruehli’s case, even though it has been withdrawn, offered a window into how Cosby’s accusers may seek to prove their claims. Because many of the incidents took place decades ago, there is no physical evidence. Instead, Ruehli sought corroborating witnesses. As part of her lawsuit, she located her boyfriend at the time of the alleged incident. In a deposition, the boyfriend testified that Ruehli had told her about her encounter with Cosby.

“She said that his penis was exposed,” the former boyfriend testified, according to a previously undisclosed deposition transcript obtained by The Post.

Asked why they did not report the allegation to the police, the former boyfriend said they doubted that officers would believe the word of a talent agency secretary over the word of a celebrity: “We figured we’d be laughed at.”