Dave Grohl tells crying drunk man to 'get the f--- off stage'

One particular Foo Fighters fan is about to have the worst hangover regret of his life.

During a Foo Fighters gig in Colorado on Sunday night, front man Dave Grohl invited a blotto man named Anthony onstage to sing along to 'My Hero'…only to kick him off when he tried to linger too long.

Dude, it's not your local karaoke joint on a Saturday night, it's a Foo Fighters gig!

Watch the clip above to see the uncomfortable event unfold.

If you're wondering why Dave, 46, is on crutches in the video, check out his recent nasty onstage fall that resulted in a fracture in the footage below…