Druski's saxophone gag at the BET Awards hit all the wrong notes with one of hip hop's biggest power players ... because TDE President Terrence "Punch" Henderson says the comedian did SZA and Doechii wrong.

The Top Dawg Entertainment boss blasted Druski after the host's running "wrap it up" bit cut short his artists' acceptance speech Sunday night at the Peacock Theater in Los Angeles.

Check out the clip ... as the pair accepted the BET Her Award for "girl, get up" the saxophonist suddenly took the stage and started playing over them ... drowning out the rest of their remarks.

Punch wasn't feeling the joke one bit. He jumped on X shortly and blasted Druski in a post-then-delete ... "This n**** Druski weird for that Sax stunt."

To be fair, Druski warned everyone this was coming.

During his opening monologue, Druski joked there'd be no long acceptance speeches or "struggle stories," telling winners they'd have 30 seconds before saxophonist Kenneth Whalum started playing them off the stage.

Druski even gave the audience a preview of exactly how it'd sound.

Looks like SZA and Doechii learned the hard way ... the warning wasn't just another punchline.

Bottom line ... Druski promised to keep the show moving, but Punch seems to think his artists got played off before they got their moment.