Diane Keaton attended Jack Nicholson’s birthday party before her death

Diane Keaton was the life of the party until the very end.

The Oscar winner attended her “Something’s Gotta Give” co-star Jack Nicholson’s birthday bash before her death, according to her “Book Club” co-star Ed Begley Jr.

“I saw her fairly recently at Jack Nicholson’s birthday party, and it was good to see her there,” Begley Jr., 76, told People on Saturday, the day Keaton died at age 79.

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

Begley Jr. called Keaton “a wonderful actress” and “wonderful lady,” noting that they also played siblings in the 1992 TV film “Running Mates.”

“So I’m glad I knew her these many years,” he added.

Keaton and Nicholson, who celebrated his 88th birthday on April 22, famously starred in “Something’s Gotta Give.” The 2003 rom-com, directed by Nancy Meyers, follows two professionals who fall in love later in life.

Nicholson hasn’t publicly reacted to Keaton’s death yet.

Meyers, for her part, remembered the late actress in a heartfelt Instagram tribute on Monday.

“As a woman, I lost a friend of almost 40 years – at times over those years, she felt like a sister because we shared so many truly memorable experiences,” Meyers, 75, wrote. “As a filmmaker, I’ve lost a connection with an actress that one can only dream of.”

“She was fearless, she was like nobody ever, she was born to be a movie star, her laugh could make your day and for me, knowing her and working with her – changed my life,” the director added. “Thank you Di. I’ll miss you forever.”

In her 2011 memoir, “Then Again,” Keaton wrote that she initially thought “Something’s Gotta Give” would be a “doomed project,” but it ended up being her “favorite film.”

She also revealed that a check “with a lot of zeros arrived in the mail for my back-end percentage,” later learning that Nicholson gave her a portion of his percentage from the film’s gross.

Keaton, whose career spanned more than half a century, died Saturday in California, her family confirmed. A cause of death was not disclosed.

Friends of Keaton’s claimed her health “declined very suddenly” and she “lost so much weight” in the months leading up to her death.

Keaton was last seen publicly in late 2024 during a holiday shopping trip.

After news of Keaton’s death broke, she was honored by her former co-stars like Goldie Hawn, Bette Midler, Steve Martin, Mandy Moore, Woody Allen and Leonardo DiCaprio.