Nick Diaz Smokes Huge Joint With Tommy Chong

UFC fighter Nick Diaz just lived out every stoner's biggest dream ... by takin' part in a smoking sesh with the Weed King himself ... Tommy Chong.

It shouldn't come as a surprise ... Diaz is notoriously 420 friendly. He was suspended for testing positive for pot last year ... and Chong is, well ... Tommy freakin' Chong.

Check out the clip ... fighter Joe Schilling also joins in on the fun.