Diane Keaton attended A-list actor’s birthday party in one of her final public appearances

Diane Keaton attended the birthday party of her “Something’s Gotta Give” co-star Jack Nicholson in one of her final public appearances before her death at the age of 79.

“I saw her fairly recently at Jack Nicholson’s birthday party, and it was good to see her there,” Ed Begley Jr. told People on Saturday just hours after Keaton died.

While he did not disclose the exact date of the party, Nicholson turned 88 in April.

“She loved Jack Nicholson, as I do, and Jack loved her. So I don’t mean to speak for him. I’m sure he’s as devastated as I am by her loss,” Begley, 76, continued.

The actor became emotional as he reminisced on working with Keaton, whom he described as a “wonderful actress” and “wonderful lady.”

“I played her brother in an HBO film called ‘Running Mates’ with Ed Harris,” he recalled. “So I’m glad I knew her these many years.”

That same month, Keaton appeared happy and healthy in her last Instagram post in honor of National Pet Day.

Following her sudden death, a friend told People that the movie star’s health had “declined very suddenly” in recent months, but she and her tight-knit circle “chose to keep things very private.”

Her longtime pal Carole Bayer Sager went on to reveal that she was “stunned by how much weight [Keaton had] lost” when she last saw her less than a month ago.

A source added that the mother of two “loved” her Brentwood, Calif., neighborhood, where she lived for many years, and that “up until just a few months ago, she’d walk her dog every day.”

To the surprise of those who knew her, Keaton — who battled both skin cancer and bulimia during her life — listed her “dream home” in March.

“Her family has asked for privacy in this moment of great sadness,” a rep said while announcing the news of her passing.

It was later reported that the Los Angeles Fire Department had responded to Keaton’s home just after 8 that morning and transported her via ambulance to a local hospital.

Her cause of death has not yet been revealed.