Beyoncé Helps Diana Ross Celebrate Her 75th with Impromptu Rendition of 'Happy Birthday'

It was a very happy birthday indeed for legendary Motown singer Diana Ross, who rung in 75 on Tuesday with an unplanned performance from Beyoncé.

The Supremes icon celebrated her milestone at a star-studded gathering at the famed Hollywood club Warwick, before later moving over to the Hollywood Palladium.

In attendance were members of Diana’s large family (daughter Tracee Ellis Ross, son Evan Ross, and daughter-in-law Ashlee Simpson, among others), as well as longtime friends like Motown founder Berry Gordy and a multitude of stars — including Sean “Diddy” Combs, DJ Khalid, French Montana, Kris Jenner, Kourtney Kardashian and Khloé Kardashian.

All gathered around what Tracee dubbed “the biggest cake ever” to sing Diana “Happy Birthday” in social media video from the party. But the Blackish actress, 46, saw Beyoncé in the crowd and quickly called the “Single Ladies” songstress over to lead things off instead.

Beyoncé, of course, delivered a “***flawless” version of the tune. Her hair pulled back in a long braided ponytail and wearing a black gown, she commanded the room — everyone staying silent as she sang the beloved melody to a beaming Diana.

The emotional moment was captured by the cell phone cameras of onlookers like Khloé, who shared the moment to her Instagram story. The Hollywood Palladium’s Instagram account also shared video of the scene, which ended with Beyoncé and Diana embracing in a loving hug.

This isn’t the first time Beyoncé has serenaded the singer.

In 2000, the 37-year-old songstress covered Diana’s 1980 disco hit “Upside Down” alongside her Destiny’s Child bandmates for VH1’s Divas Live tribute concert to Diana’s illustrious career.

Beyoncé has also cited Diana as an influence on her musical style, even playing a fictional girl group singer turned solo star based on Diana in the film adaptation of the hit musical Dreamgirls.

Diana has been celebrating her 75th birthday for weeks now, hosting a “birthday celebration” in Las Vegas with a series of shows at the Wynn Las Vegas throughout February.

“Thank you for being here to celebrate my 75th birthday,” she said to large applause, before walking through the crowd singing “Reach Out and Touch (Somebody’s Hand).”

After telling the crowd “don’t be lazy” as she prompted everyone to stand, she ended the performance by exclaiming, “Happy birthday to me!”

With all these performances, it shouldn’t be a surprise to hear that Diana actually took the stage at her own birthday party on Tuesday, too.

According to Instagram stories from DJ Cassidy, the set at the Hollywood Palladium included Diana collaborating with Diddy on a mashup of her hit “I’m Coming Out” and his hit “Mo Money, Mo Problems” — which sampled Diana’s tune. Diddy’s three daughters then danced alongside Diana for a performance of “Stop in the Name of Love.”

Other songs performed by Diana included “Come See About Me,” “The Boss,” “Your Love,” “Ain’t No Mountain High Enough,” and “Endless Love” — which she sang with Robin Thicke. Evan and Simpson dueted on “Love Hangover,” while Khloé and Kourtney danced on the stage with mom Jenner and Diana as she sang “Turn Me Over” and “Ease on Down the Road.”

Stevie Wonder made a special appearance at one point, singing his own “Happy Birthday” to Diana.