Chris Brown -- I Have Custody of Royalty ... On Stage!!! (VIDEO)

Chris Brown didn't take Royalty to the zoo during his first full day of custody ... he brought her on stage at his concert.

C.B. and the 1-year-old were cheered on at the Isleta Amphitheatre in Albuquerque.

TMZ broke the story, Chris just won temporary joint custody of his kid ... he and baby mama Nia Guzman rotate 4 days each.