Hayden Panettiere claims an “Oscar-winning actor and director” exposed himself to her when she was 19.

The “Nashville” actress, now 36, details in her newly released memoir,  that the shocking situation happened after a friend invited her to an “industry” party at her Los Feliz, California, apartment.

Noting that the party consisted of just her, her friend and “a small group of men, who were gathered together, talking, drinking, and smoking weed,” she recalls feeling immediately uncomfortable.

“These men seemed to be a little too comfortable together, like they knew something I didn’t,” she writes.

She goes on to detail that, after about half an hour, she was about to say goodbye to her pal when the Oscar winner approached her.

He wished her a good night and warned her to “be careful when you leave because someone spit their gum out somewhere, and I got some on my pants,” before allegedly directing her to look down.

“I looked down and recoiled,” she writes. “This well-respected, award-winning actor’s testicles were hanging out from his unzipped fly.

“Men in Hollywood had always been kind and respectful around me. There may have been a peck on the lips here and an inappropriate comment there, but nothing had crossed a line.”

She adds that the incident “hadn’t hurt me” but left her “shocked.”

Elsewhere in the book, the “Bring It On” star details her physically violent relationship with ex Brian Hickerson, which was marred by multiple domestic violence incidents and arrests.

Panettiere also opens up about her relationship with “Heroes” co-star Milo Ventimiglia, whom she dated when she was 18 and he was 29; comes out as bisexual; and writes about her complicated relationship with her estranged mother, Lesley Vogel.