Predictably, it was incredible!
"Thank you for being here to celebrate my 75th birthday", she said to large applause. Other family members, including Ross' daughter Tracee Ellis Ross and son Evan Ross, were also in attendance and cheered him and the singer on. But the limelight was nearly stolen from right under her nose, by her own grandson - 9-year-old Raif, the son of her eldest daughter, Rhonda Ross Kendrick, 47.
"She is wonderful", he said. "I'm nearly 4 foot 9".
Shortly after, she segued into "Reach Out and Touch", embracing the crowd as she made her way towards the middle stage while also calling for unity among her peers and fans - including Jaden Smith.
The music icon then asked the audience to sing along with her. "There's only success ahead, and you can lead the way".
"She is awesome", he told the audience about Ross. Diana ended her performance by saying, "Happy Birthday to me".
The singer - a proud mom and grandmother - was joined by her kids and grandchildren who were in the crowd to watch her "Diamond Diana" performance. (There were scheduled to be even more big acts taking the stage, but several artists - including Ariana Grande, rather publicly - pulled out from the ceremony.) As for this year's nominees, Kendrick Lamar began the night on top with eight nominations to his name.