Reese Witherspoon fought back tears as she publicly honored the late Diane Keaton.

The “Morning Show” actress became emotional while speaking about her personal relationship with Keaton onstage at her media company Hello Sunshine’s Shine Away event in Los Angeles Saturday.

“Diane was really important, she was one of my first mentors in this business,” Witherspoon shared in a video she posted on her Instagram.

She explained how Keaton became a guiding light after she auditioned for the “Annie Hall” star when she was just 15 years old. Witherspoon, 49, recalled how Keaton immediately cast her for 1991’s “Wildflower,” a television film that Keaton directed.

Witherspoon starred as Ellie Perkins in the film, who, alongside her brother Sammy (played by William McNamara), helps an abused, partially-deaf girl named Alice (played by Patricia Arquette).

The “Big Little Lies” star said it was only her second or third movie audition and that Keaton was taken by her “big country accent.”

“She goes, ‘Who are you?” Witherspoon humorously recalled. “And I said, ‘I’m Reese Witherspoon and I’m from Nashville, Tenn.,’ And she said, ‘Are you making that up? That accent you’re doing?’”

Witherspoon praised Keaton as “incredible” as well as a “truly unique person.”

“So for Diane, watch one of her movies and wear a really cool, interesting outfit, black and white,” Witherspoon said.

“Take a cool picture and just live your dream,” she continued. “Just be your unique, interesting self, I think Diane would be really happy.”

Witherspoon also shared a sweet message about Keaton in her Instagram caption.

“Diane Keaton changed the way we all saw women on screen – smart, funny, stylish, and completely original,” she wrote. “I’m so grateful to have had her as a mentor. 🤍.”

Keaton died in California at age 79. Although she looked happy and healthy alongside her beloved dog, Reggie, in her last Instagram photo posted in April, a friend of the actress told People that the actress’ health had rapidly declined unexpectedly in the months leading up to her death.

Tributes poured in from the iconic actress’ famous friends following her passing, including from her “The First Wives Club” co-stars Bette Midler and Goldie Hawn, as well as her “Father of the Bride” co-stars Steve Martin, Kimberly Williams-Paisley and more.

A number of actresses shared how Keaton inspired them, including Sarah Jessica Parker.

“Diane Keaton has been a point of inspiration for countless actresses. I include myself among those who loved and admired her,” the “Sex and the City” star wrote on Instagram.

“I was very privileged to witness her singular skill and talent on both ‘First Wives Club’ and ‘The Family Stone,’” she continued. “I will cherish those memories on set as well her touching, delightful and perfectly own cinematic career. Which is a gorgeous legacy of an exquisite person.”