KRS-One -- FREESTYLIN' on a Hollywood Street Corner!

Something awesome happened to TMZ on a random street corner in Hollywood last night ... and no, it didn't involve crack or hookers ... but rather hip hop legend KRS-One.

The rap pioneer was coolin' off outside of AV club, where he had just performed a set ... when he decided to bless the TMZ camera with a FREESTYLE session ... right on the street!!!