Play video content EXCLUSIVE TMZ.com

Nelly had to hit pause on his show in Las Vegas after one of his fans did something that totally messed with his flow ... untied his shoe!!!

We just got this wild video from inside Nelly's Thursday night gig at Drai's Beachclub ... and you see him cut the music and go on a long rant after someone in the crowd reached onstage and tugged on his shoelaces!!!

Check out the clip ... Nelly was NOT having it. He paused the show for a few minutes, ranting about being too grown to have people untying his kicks, and ripping an overzealous fan for getting too close for comfort.

Fortunately, Shoelacegate didn't derail the whole show ... folks at the club tell us Nelly got back to rapping after addressing the crowd.

So, if you're trying to grab Nelly's attention the next time you're at one of his shows ... stay away from his footwear.