A Macklemore fan's big moment onstage with him took a nose-dive when she forgot she was on police radar ... with the cops swooping in and escorting her out in handcuffs.
It all went down at the Lovestream festival in Slovakia over the weekend... the hyped fan bragged about her impromptu duet with the rapper on social media -- but little did she know, her celebratory post was a one-way ticket to getting busted.
The cops revealed in a Facebook statement they immediately got a tip when someone spotted her social media post, recognized her from a police report -- and officers at the venue responded.
But they were kinda cool about it all ... letting her enjoy her moment until the song wrapped up before getting on with the arrest.
The specifics of her alleged crimes are still a bit murky ... but local reports say she’s a 24-year-old bartender who’s been dodging a fine for running shirtless during a 2019 football match in Slovakia while working as staff.
Talk about one heck of a show-stopper!