Selena Gomez Anything Justin Does, I Can Do Better ... Tumbles Onstage!

6/20/2016 6:47 AM PDT

Selena Gomez will tell ya ... that first step can be a real bitch when you're performing in front of 19,000 people.

She had a gig in Tulsa Sunday night, and her attempt to go down a short flight of stairs onstage did NOT go smoothly.

Instead of falling for Justin Bieber -- now she's just falling AFTER him.

Whoops…😁 How did you not see the giant hole in the floor @justinbieber 🤔😂

A video posted by Purpose Tour | Next: Fargo (@purposetour) on