"Grey's Anatomy" star and legendary choreographer Debbie Allen is still gettin' it on the dance floor with her ex-NBA husband Norm Nixon.

Norm played 12 seasons of pro hoops and Debbie's been a dancing star for decades -- so, who do you think had the better moves at her weekend white party? Check out the video.

The dance-off went down on a yacht in Marina del Rey. Debbie threw the bash for her non-profit Debbie Allen Dance Academy -- but all the students had to step and watch the couple's spotlight dance to Drake's "One Dance."

Debbie tells us she wanted to "bring joy to the kids by showing them we still got it."

Mission accomplished. "Fame" can't be 30 years old, right?!!