Matt Barnes -- I'm With the Boss ... Parties with Rick Ross

Matt Barnes rebounded from a crappy night on the court by hanging with Rick Ross and a bunch of other hip hop stars at a huge Hollywood after party.

Barnes was in the VIP at Supper Club for Rick's performance Saturday night in Hollywood. The Clippers star chilled with Rick, Wiz Khalifa, Mally Mall, and Ty Dolla Sign. Famous booty model Rosa Acosta, "Love and Hip Hop" star Sincere, and singer Anjali World (daughter of Kings owner Vivek Ranadivé) were also there.

Earlier that night ... Matt put up a goose egg in 26 minutes on the floor in the Clippers game against the Bucks, but still won ... 106-102.