It would be hard to imagine a bigger or better birthday celebration than Beyoncé's on Monday.

During the singer's "Renaissance World Tour" concert in Los Angeles, Diana Ross surprised the crowd when she stepped on stage to serenade Bey with a rendition of "Happy Birthday."

"I'm here to celebrate Beyoncé's birthday," Ross said as Beyoncé hugged her tight.

When Ross was finished, Beyoncé, who turned 42, told her, "Thank you so much, you are so amazing."

"This is the legendary Diana Ross! There would be no me without you, and thank you so much for all of your sacrifice and your beauty and your grace," she said. "Thank you for opening doors for me. Thank you so much."

Kim Kardashian was in attendance and shared a video of the two on stage on her Instagram Story, writing, "A birthday song from @dianaross."

Beyoncé had previously serenaded Ross in 2019 when Ross turned 75.