YG Cussing Out Tekashi 6ix9ine Fan in Australia

YG's beef with Tekashi69 is going way beyond West Coast vs. East Coast, because he's cussing out 6ix9ine fans thousands of miles away.

We got video of YG boarding a flight in Melbourne, and he starts yelling at a fan who flashes a 6ix9ine shirt at YG and his crew.

Check out the clip ... you hear YG swear at the Tekashi fan, dropping an f-bomb and calling him a "p****."

YG is on tour down under, but he's apparently bringing his feud with Tekashi with him. The 2 rappers have been trading barbs on social media all year, and YG's boy Slim 400 had a showdown with Tekashi earlier this month at ComplexCon.

Seems this guy was trying to get a reaction out of YG. After all, YG loooves trolling fans of his rivals.