Orlando Bloom had a run-in Justin Bieber early this morning in Ibiza. And by run-in, we mean he PUNCHED HIM!

Orlando was at the Cipriani restaurant. Justin screamed, "What's up bitch?" That's when Orlando threw the punch. And when Bieber left the crowd applauded.

BTW: There is a backstory with these two, remember. 2012. The Victoria's Secret Fashion Show. Justin was partying with Miranda Kerr, who was married to Orlando at the time. And THEN, just this past April, Orlando was hanging out with Selena Gomez.

Source: TMZ