Diana Ross was all about partying Saturday night as she impressively busted some classic moves.
Diana and her son, Evan Ross, hit up The Abbey in WeHo ... possibly the most famous gay club in the U.S. The crowd was more than ready for the former Supreme who showed everyone -- at 73 -- she's still got it.
When the DJ cranked up "Ain't No Mountain High Enough" the crowd went crazy as Diana grooved.
On her way out our photog asked about sexual harassment.