The rock band took the stage at Comerica Park in the Motor City Wednesday night ready to bring the house down ... but, during their song "Longview," someone from backstage sprinted out and grabbed the bass player, Mike Dirnt, directing him offstage.

Lead singer Billie Joe Armstrong notices Dirnt leaving the stage, stares at him for a moment, then books it after him ... all while fans kept the song going ... even as the house lights came up.

After a few moments, a big notice pops up onscreen ... telling fans the show was in the middle of a "show pause."

According to reports, someone flew a drone into the stadium ... forcing Detroit Police to clear the stage to ensure the band's safety. Detroit Police Cpl. Dan Donakowski tells the Detroit News they detained the man who allegedly flew the drone, pending further investigation.

Eyewitnesses say the stage remained deserted for about 10 minutes before the band walked back out and resumed playing.

GD went back out and finished the song ... and Billy Joe reportedly told the crowd "ain't no motherf***** that's gonna stop us, I'll tell you that" -- so, the scary incident didn't soften their vibe. The band later apologized to fans via X for the delay.