8:30 AM -- Justin's date was Baskin Champion, and he's very familiar with her family. Baskin's sister is Abby Champion, gf of Patrick Schwarzenegger ... who's JB's BFF.
Got all that?
Justin Bieber's rebound game was in full swing as he left a Sunset Strip concert with a mystery chick.
The Biebs, who normally gravitates to brunettes, threw a change up outside the Roxy Tuesday night by opting for a blonde companion. It's his first public hook-up, post-Selena Gomez, and Justin tried their best to go undercover as they bolted out of Craig David's show -- she got into their waiting SUV first, and Justin followed about 10 seconds later.
Considering the pics we got of Selena hanging with friends, including a mystery guy, on a yacht in Australia ... fair to say they're both moving on. For the umpteenth time.
Blonde chick aside ... Justin did something else he hasn't done in a while -- he got on stage at the Roxy. Craig David invited him up, and Bieber showed him a lot of love.
Turn the page.